1. That's actually the most complicated idea. When someone decides to make their Pokemon hold it, the gain is very intangible. You don't know how many Pokeballs to buy, because you don't know how many Pokeballs you really have. It also seems hardest to program. What if you switch out that Pokemon before catching or it faints?
2. If there's no point where money is tight, there's on point having money at all, don't you think? The whole point to having money is to force decisions on how to spend it.