I don't feel household chores are something anyone should get paid for. Nobody pays me to do the laundry, dishes, etc, why should kids get paid for contributing as the rest of the family does, and cleaning up after themselves?
However, going above and beyond, that I think should be rewarded; money in exhange for time. Hence the money to help with the weeds. And believe me, that is not an every week occurance. I used that as an opportunity to show my five year old how if I hired him to help with the weeds for two dollars, he could then hire his little brother for one dollar, and have his brother do the work, learning to leverage OPT (he didn't do it, but hopefully the idea will stick).
Our kids don't get paid for chores. Yes, they do get a small allowance to teach them how to budget and save, and to let them make mistakes and learn from them. But we keep the allowance and family responsibilities entirely separate. The two don't have to (and probably shouldn't) be linked. Our kids are expected to do their (age-appropriate) chores regardless, simply because they're part of the family. If they go over and above the call of duty (like when my nine year old spent an entire afternoon under the house helping me install a new vapor barrier) they get a little something extra. It's worked very well for us but, by all means, do whatever works best for you.