Compared to Champions Online or Star Trek Online, I would agree with the stingy observation. I have only played one other MMO (Neverwinter Beta) and did not get far enough to make an informed observation. With SW:TOR, I dropped a few bucks on it (extra movement stuff and additional crew (gathering/crafting) skills and went to preferred status. The two biggest advantages are the ability to e-mail objects (not credits - sub only) to other players and the ability to trade between players. Having six character slots is nice also. The one thing I really like about SW:TOR is the storylines. They are voice-acted pretty well and engaging enough that I can look past the MMO aspects of the game. As I progress further into the game, the story aspect gets weaker though and the MMO grinding gets stronger. I may not actually finish the game if the trend does not stabilize into a happy medium soon.
One of my biggest complaints about the game is that Jedi are among the weakest of characters. The Trooper/Bounty Hunter are both more sturdy and able to deal more damage out to larger groups of enemies. That's a design thing though. I have not had many problems actually surviving but I often think "my Commando (Trooper prestige class) could have done this easier/with less damage taken." While I don't want or even think it appropriate to have Jedi monstrously more powerful than anybody else, they should not be flimsy either. The same cannot be said of the Sith side of the house. My Sith Warrior (the Sith mirror to the Jedi Knight) seems to be just as powerful as my Bounty Hunter (Sith mirror to Trooper). I did note that some people on the SW:TOR forums mentioned that the Jedi Knight does not come into their own until the mid 30s level range. I'll have to see about that.