I just rode a ski for the first time the other day. I loved it, and now I want one

How do you know what to look for in a used ski? How do you know if its a fair price? Should I get stand up or sit down?

I'm 5'6", 130 lbs, female in Pickering. I rode a sit down the other day. I did some small wake jumps and some 180s. I'm worried I won't be able to do many tricks if I get a sit down, but I do like how the sit downs can fit multiple people and I can waterski behind them.

Any advice would be appreciated