In your price point, there isn't much, however the one that falls squarely in the zone is a Keltec Sub2K. I have a gen 1 in 9mm and it's a great little rifle. Tough as nails, and when folded in half is a REALLY compact and very light little rifle to carry. Out to a hundred yards or so, dead accurate; you should have no trouble putting 100 out of 100 rds on a 8 in. pie plate with factory sights (which suck, BTW). The Gen 2 has rails standard, improved sights, and improved ergonomics.
The problem now, as always is finding one new, or a good used one. Keltec doesn't make any more than they can sell immediately, so everyone seems to be back ordered on them. Used can be a crap shoot. They often wind up as truck or airplane guns, bouncing around in the back until you need it. They tend to get banged up from that kind of abuse. Mine is my trunk gun, but I keep it in a locked, padded case to keep it looking and working well. Another problem with them is since they are a bit tough to find, there are a number of scam artists around. I got ripped off trying to buy one...here as a matter of fact...and I have talked to five other people who had the same experience, different "sellers".
Don't shy away from them because they are mainly polymer...someone that says they're weak or flimsy because of that almost certainly hasn't owned or shot one much. I've had mine for three years, it's shot several thousand rounds, it lives in my trunk year round, and goes bang every time I pull the trigger.