I've been collecting for about 30 years now too, and have only recently slowed down significantly. I'll still buy a few trades a month, but I'm basically done with singles. Don't think I have anything that's worth much (mostly Marvel stuff from about 1990 with a few older keys), but I still have everything in several boxes and filing cabinets (legal filing cabinets are great for comics storage).
Main reason I slowed down wasn't money, more just getting bored with a lot of what's out there. Consequence of being in for this long-everything repeats eventually, and momentum is incredibly dangerous. There are many many titles I kept buying for far longer than I should have just because they were already on my pull list. That's why I've started batching things in trades, and waiting until something looks interesting before jumping in. There's still some great stuff out there though: Kieron Gellen's latest series Die is fantastic, and Saga, Sex Criminals, and The Wild Storm are all really good. I've also been enjoying the last batch of Marvel Star Wars stuff.