We have tried several things over the years.

Chore chart - SD is with us every other weekend. She has dishes Friday night, empty dishwasher Saturday and vacuum, help SS clean their bathroom on Sunday....So, it's not a lot of time consuming chores but she is expected to contribute to the household. SS lives with us full time and has small chores every day. More time consuming chores when he is home during summer break.

Two hrs of screen time a day. Period. Both are grounded from this at this point for bad behavior and grades.

They get money for grades and I was giving them $5 a week for allowance. The allowance wasn't earned by doing chores on the chore chart but was taken away based on certain factors...Lost $1 for not wearing deodorant (used to be a big issue) loss $1 for leaving dirty laundry laying around. Small amounts for things that we have talked to them about over and over and over.

They could also earn extra money for doing certain things, like pulling weeds, cleaning the car, taking out the trash. Each extra chore had it's own price based on difficulty and time.

I never gave money for chores, because I never wanted to give the impression that exchanging household work for money was an "option", I was more interested in teaching them that it's a necessity. They each had a chore every day... and it was expected they do it. If they didn't, no screen time, no game, no fun stuff... it just wasn't an option. You do your chore. Period.

I've also never paid for good grades - I've only punished for bad ones, however my oldest is in 10th grade now and is realizing that he can't get away with minimal for good grades... he's gotten a few crappy ones - so I told him that if he has all A's, I will give him 100$.

I don't have experience with money/screen time, but I did used to do something similar with "extra chores" - they'd complete them for some additional fun time, since they were limited on screen time.

As far as learning the value of money.... what I ended up doing, by happenstance, was that my son wanted a toy... I told him that if I bought him that toy, I wouldn't have money to buy groceries for his snacks... he said it was ok.... ooookkkk buddy...

I bought him the toy. Next time he asked for a snack, I didn't give him one, and reminded him that he chose the toy over snacks. He'd eye his sisters' snacks hungrily. Later on, same thing... sorry kiddo, the money for your snacks went to the toy you wanted.

Finally he said he wanted to take the toy back so he could have some snacks...

I took out a pile of change - made up cards with things and money on them... I totally exaggerated them... picture of milk, with 3 dollars, picture of bread with 2 dollars, picture of chicken with 5 dollars, picture of toys with 12 dollars... and handed him the fake money... he had to put the money on the pictures of money on the drawings... realized quickly that if he only had 13 dollars and 12 went on the toy, there wasn't any leftover for milk, bread, chicken... he was about 6 at the time I think. He also eventually realized that if he spent 10$ on milk bread and chicken, he had 3 left over to set aside... every time... so after 4 times... he could have both the food AND the toy....

SO really doesn't have much impact on school since the kids are so young. The oldest does well and the little one is in preschool. Right now his "grades" are how well he behaves every day and since it's not fair for SO to have to correct his behavior 3 days later he doesn't try. Basically school is on BM since she has them primarily during that time while SO has made it clear he wants them to do well.

As for chores the kids are required to clean up after themselves with no incentive. It's their room it's there responsibility. They do earn an allowance type thing on was we consider house hold chores. These are things like doing the dishes and laundry since those belong to the full house. They are asked to complete so many of these tasks then given money when they reach it. Like do 10 'chores' and you get 5 dollars. Currently we don't MAKE them do the chores so they get natural consequence. We've asked little one to load the laundry before and he's said no so we then ask older one. She does it and there for gets money sooner. When little one notices that she is using her money to buy x item and wants to know why he doesn't have money we remind him that he said no to doing the chores so he doesn't get the reward. It's a work in process that he's starting to understand and the oldest JUMPS at the chance to do the little ones chores because she sees the benefit. We offer equal chances to do chores at the start.

Screen time is at our choice and will not be allowed if there is misbehavior. You want to play x-man... well you hit your sister today and remember we said no video game becuase of it. The kids get to use the tablets and such so much with BM that they really don't ask to do it that much at our place. They honestly seem to prefer playing with their toys and such. It's really quite sad. We've dropped them off at granddad's before and they jumped right on the tablet I joked with the oldest about going to play with something and she said they didn't have toys there......

This is what works for us.

Year round SS15 has weekly chores such as take out trash and vacuum. He does his own laundry and we rotate on who washes the dishes between the three of us.

During the school year we do not give him any money for doing these things. He goes to school, baseball after school, homework, dinner and maybe time for a show or he reads and then bed. His weekly chores are still done on the weekends.

During the summer he has more down time while SO and I are at work. We give him $50 every other week and that is for extras over the weekly chores such as yard work, washing the cars, cleaning the bathroom or doing our laundry (MY favorite chore for him to do - he's good at laundry) He saves some and some is spent on movies and days out with his friends.

You're luck if your DH is on board with this and will support you.

I tired of trying to get DH to open a bank account for each SD, years of trying, and still nothing (they are 11 and 14). Not even BM does it for them. They want one. So I disengaged.

Chores is a dirty word in our house. I disengaged from that as well for two years. DH is now, just now, staring to ask me for help with that - but I'm putting severe limitations on this for myself and for him.

I wouldn't pay for grades.
I also wouldn't pay for general chores that everyone should do anyway like help clean up after dinner, clean rooms, etc. I would pay for extra stuff like vacuuming, pulling weeds, cleaning up the garage, etc.