Why am I stashbusting but the stash is growing?

I keep seeing beautiful yarn that I want to put in my sweater. I'm obsessed with this sweater now....every gorgeous colored, soft yarn is going into it. I only hope it fits me, I hate to frog and start over. But start over I would.

Handcrafters House in Midland, buying a gift for someone else, and scored two balls of Naturally Kid et Soie (70% Mohair, 20% silk and 10% NZ Merino, this stuff MELTS in your hands!) in cream and blue. And for a bit of BLING, Sunbeam Paris Mohair, gray with sparkly bits.....all for 40% off!!
I did leave a few balls if someone else needs them :)
Michelle