I really like the top break feature of the H&R 999. A 999 was my very first handgun. Cost ~ $100. Loved it for a while until I realized that it had problems (timing, and cylinder gap) and I retired it for a new Colt Diamondback for about $100 more. 22LR Diamondbacks now run at least $1000 in excellent condition and I suppose the H&R is being dragged along behind the Colt and S&W 22 revolvers. But I feel much like SaxonPig in that it is at best a medium quality 22 revolver and I just don't see much value over $250, $300 tops.
Despite if S&W may or may not be better, they are more expensive and I more like the H&R 999 Sportsman for the looks. I've always wanted a top break revolver and preferably in .22lr.
I wish S&W made a top break 22 revolver. I'd buy that. Like I said, I really liked the top break feature.
If I had to pay $450 for a used 999, I would buy the much better made S&W Model 17. (There is no doubt in my mind that the S&W is higher quality.) I purchased my last one for $550 OTD. But they sell on average for a bit more now; $650-ish for a nice one. I'd stil pay the extra $ for the S&W. I saw a slightly used 4" M63 for $400 and I consider that a better made 22 revolver.
So, I don't see the value people are placing on these used H&R 999 revolvers over what I know to be better made S&W revolvers. However, I would prefer one over a new Taurus M94 if they were priced equally and the H&R was taken care of.