A sort of deadline or countdown sounds good, I need to find a place to put it. In the game I displayed several message box popping up, reminding you of both deadlines, but it's easy to skip them while clicking.
Regarding prices it's probably that I increased the gold reward too much because my concern was to not leave players without money. In the adult age, if you notice when the customers come asking you for an item, that item is automatically removed from all shops (otherwise the text wouldn't make sense, the customer says "I've looked everywhere and can't find this!").
It's a system to avoid that "cheat", even if after a few days the shops restock so you could still manage to do it (but it's not easy as it is normally).
I could use this "trick" also for the other jobs, but I want to know more opinions first. This because maybe you're a good player but I need to take into account a sort of "average skills" of all players
). I made an openoffice spreadsheet with all the prices before coding them in games but indeed you wouldn't make much money for each piece (except at high levels) because I thought would be too easy, but while playing I had to raise the task money, so clearly something is a bit off 
