You need to differentiate between the coins , these are what you get daily on your spins , or that you win in the head to head coin rooms. It’s these you then use to upgrade your apparel . These are different to the credits that you use to buy balls or equipment , and that you can get by watching videos , doing surveys or completing offers.
Of course , both credits and coins can be purchased with real money , but it’s not necessary.
WGT have made their rules for which can be used for which transaction , you don’t have a choice .
ideally you want to build up coins if you want to have best apparel , or wager in the higher coin rooms. You want credits for buying balls, passes and better equipment.