something reliable, accurate, but less than an arm and a leg?
Accuracy of a pistol caliber carbine is going to be
pistol accuracy. Gallon milk jug at 100 yards is typical. Auto pistol calibers are intended to be used at 50 yards or less, so don`t expect tactical rifle performance at longer ranges.
The Ruger PC4 & PC9 carbines are pickup truck rugged and reliable little carbines. They were quite literally designed to knock down doors with a butt stroke. Police sales were not enough to keep the guns in production, leading to their discontinuation. They are still widely available around $250. These carbines take magazines used in the Ruger "P" series pistols.
I had a PC4 for a while and was satisifed with it. It was a fun toy but was replaced with a Kel-Tec.
The Kel-Tec Sub2000 carbine is a great plinker. I have one in .40 caliber, that uses SIG P226 magazines, and have no intention of selling it anytime soon. The Sub2000 folds in half, to 16.25" long for storage or transport. The gun will fit easily into a standard brief case when folded.
There are several models available, in either 9mm or .40S&W. The gun is handy and very reliable.
You can get one in your choice of 9mm or .40S&W that will accept either (one of) Glock, S&W, or SIG magazines. Kel-Tec has a good reputation for standing behind their products, so you can buy with confidence. I paid around $300 for mine, new, a couple of years ago.
Availability of a specific variation can be spotty as they are run in batches throughout the year. I had to wait a few months to get the variation that I wanted, The Sub2000 has a loyal following and there are many factory and aftermarket accessories available. There are a couple of internet forums for Kel-Tec owners that would be worth researching for more info.
While the pistol caliber carbines are well suited for plinking and most "survival" scenarios, I would strongly recommend a lever action carbine in .357 Mag or .44 Mag if you seriously intend to hunt with the gun. They will have an accurate range of 100 yards or slightly more and much better accuracy and power at this range.
Jack