[Tha Stunna]

I'm not much of a razz player; be warned.

Actually, the chance that villain has paired is much less than dealing out random low cards would predict. If villain doesn't suck, then he doesn't have an 8 in the hole; it's not healthy to draw to an 8-7 low. That means you are only ahead if the three paired him, and you already have a three.

This would be less true if he flat called in a late position before anyone entered, for instance.

One benefit of raising is that you can fold unimproved on the river if he 3 bets; you know you are beated, unless villain has steel (or perhaps just iron) balls. There's also an off chance that he's very loose-aggressive (which I suppose also means that he has steel balls), but you should have noticed that by now.

I don't have a recommendation here, but if he sucks then just raise.