I am new to Ultimate Team, no money spent.
I hadn't spend any of my coins since the game came out, until last week - I decided to buy a few cards to round out the weak spots on my team (I use this site to check prices so that I don't overpay). I pulled a card in a pack that was better than one of the cards that I recently bought, so I went to auction the one I bought and noticed that it had lost a lot of its value in just 1 day. I am reluctant to buy more cards because of the market depreciation, but I also think that waiting for prices to go down can be pointless...
What do y'all take into account when buying cards? How do you know if it's a good time to buy?