The expansion packs are what they are, imo, the way each new base game installment essentially resets the party is almost always a step down at first, but inevitable. Like with Sims 3, it tends to get better once the new content is added... and I wouldn't say the existence of these packs are innately negative as much as the lesser of two evils (getting probably left with nothing at all or what have you) -- it just comes down to how good they are and in what manner they are distributed.
But they do add up and it can be daunting just how much content is split into all these multi-priced extras. And in 4's case, they've been churning them out at a faster rate than before if I'm not mistaken, and with a newly introduced pack category to add to the pile and the like.
I do love The Sims I confess.... The bottom line is that altogether we are provided a very meatified life/dollhouse sim that 60 bucks for everything would feel like a steal for in retrospect, yes. You don't need to buy everything at their most inconvenient pricing to have a gameplay experience that contains sufficient content either. I never had all The Sims 2 expansions and it's my favorite in the series. But when you see just how much content is being sold, it's definitely a buttload of numbers for one single player game. But it's one crucial way EA supports the series and the fans are actually very active in interaction with them and in voicing what they want so it's all part of the deal really.
Milk the cow, take the calcium!!