I'm not certain yet. I've bought a few AR15 lowers and a few more magazines for my G19, but nothing more.
Before the last AWB, I bought a bunch of G19 magazines and a Mak-90. I've only shot the Mak once and the magazines, while nice to have, mostly just take up space.
I've been thinking about building an AR15-type gun, but don't really want one, don't have a good place to shoot it, and don't have the space. Still, the prospect of not being able to get one in the future does make me think about it - but the stripped lowers are as far as I've gotten.
I'd get more use out of another shotgun, maybe some cowboy guns, and maybe a 642.