Tec-22. Biggest POS ever made and widely distributed. As you shoot it the top cover holding the bolt in and the sites bends.
But Cheapest is the pair of 22 revolvers I bought at a gun show 23 years ago, $20 for the pair. Technically they work, but are really rough. Bought them to practice fixing revolvers on.
Recently, bought a used Ruger EC9 from the gun store. $109 out the door. Sure, I bought, and was given, cheaper things like 22 rifles.
I just thought it was a good deal.
I almost hate to repeat this tale; but an associate in Corpus sold a nib British 20GA sidelock SXS and a nib Anschutz .22, oiled hand cut walnut, for $150 the pair. Said “Wife didn’t want guns in the house” ! I had advised keeping them for his Grandsons out in Jim Wells County.