unless you play skins challenge. Then you have to pony up credits for each hole., but you can win those credits from other players.
For example 4 of you play a skins game for 10 credits per hole. Each golfer puts in 10 credits per hole for a total of 40 per hole. If you win that hole/skin you win the 40 credits. so if you take 5 holes/skins that is 200 credits and you would have had to put 90 credits at risk on a 9 hole skins challenge. I believe in those games WGT takes a percentage for something i don't know what. so numbers may be a little off, but you get the idea
then you can use credits to buy stuff in pro shop