Steam makes this easy, since the expansion packs are treated as DLC on there, and Steam gives a total for all the available DLC.
Even at the current 50% holiday discount it'll still cost almost €230 to get all the DLC. Even if you leave out the stuff packs, it'll still cost almost €150.
And that's excluding having to buy the base game. It's ridiculous, and it's one of the main reasons I haven't bought a Sims game since I got The Sims 1 and an expansion pack about a decade ago.
I just checked the prices in dollars, and now I'm pissed off. The base game is 22.50 euros, but 15 dollars. The DLC price difference is 20. The euro is worth MORE than the dollar, not the other way around, EA :|