Reading For Cash

Homework time at my house is a nightmare.Zack is pretty good about getting his done and I just have to check it and he will do his 30 min of reading right before he goes to bed.Ben and Ulia on the other hand it's like pulling teeth to get it done,I think part of the issue is there ADD meds are wearing off by the time they get home and focusing becomes an issue.They can't sit dowm together and do it as it's way to much of a distraction for Ulia.So she and I usually do hers then Ben and I do his.Ben hates to read,which drives me nuts because I love to read. So it came to me last night what is Bens favorite thing in the world?....to Have money! the boy can save money like no other.So last night I told him if he reads each of his book each night(usually 3, 5-10 page books) without any issues or playing around I would give him a quarter for each one,but if he fussed or played around I would get a quarter back for each time he acts up. So is it wrong to bribe him to read?