Asking for a digital proof first is solid advice—especially when trying to match paper stock or foil seals for a prop project. The point about watching out for unexpected fees is so true for online specialty printing. Custom additions like heavy parchment or rush shipping can easily double the total cost if you aren't paying attention.
Having clear pricing up front makes budgeting for any personal project or group event so much easier. It really applies across the board, whether you're pricing custom prints or even just planning a casual team gathering where you need an updated Tim Hortons menu pricing guide to figure out exact catering costs beforehand.
Checking Etsy or local print shops is a great alternative too—local shops in particular are usually pretty helpful if you just want a single sheet printed on nice, heavy cardstock without paying high shipping fees.