I have two pay-site subscriptions going at any given time and have purchased download packs from a number of other sites. I have a complex system of figuring out what the value of any given set/item subscription is to me before I pay so I rarely feel cheated.
I'm fortunate that I don't have a lot of costly habits or hobbies so I don't feel bad about paying for some things that I really like for a game that I devote a lot of time to. I still spend about half as much a year as my boyfriend does on cigarettes, and game objects can't kill me.
I also like the EA objects/textures a lot. I know purchasing the stuff packs just encourages EA to make more so to make up for it, I give my replaced EP/SP discs to my sister so she doesn't have to buy it herself.