Hi there-1) It is really hard to gauge how much to take- because you never know what people will want to buy, and that can change from show to show, or day to day (at a longer show).-Definitely take back stock, but don’t make yourself crazy by second-guessing what people will want.How about this- take a bin full of extras, and make sure you get enough sleep the night before (instead of worrying that you don’t have enough)! Also you can have pictures of sold-out items and see if you can take orders for them.2) I just take cash and checks- I have never gotten a bad check in years of doing shows and selling wholesale (knock on wood). I used to take credit cards, but have stopped because they are expensive and are a pain (and it sounds like you are only selling smaller dollar items, not $3000 prints- right?).At one show I actually let someone pay me later on paypal (because she didn’t have any form of payment with her). I don’t know that I would recommend that for everyone, but if you get a good sense of someone it can be the exception.I hope that’s helpful to you- Good luck at your show!Kristin