Used rifles can be a GREAT way to save some money and get a great rifle--espeically rimfires...but just like you said, you have to know what to look for.
More often than not, general appearance will give you the best idea on the age or how well the rifle was cared for. Aesthetics will also drastically affect the value of the rifle. I've found some ugly rifles at great prices in the past...with a little cold blue, parkerizing, etc. and a little sanding and finish on the stock they can turn into great looking, fabulous shooters for little money. Many older rifles are very accurate, and often have quality wood stocks (walnut, mmm).
I'm a pawn shop junky...I love to fequent various shops in search for rimfires. More often than not, you can buy some great rifles for under $100. The nice thing about .22lr's is their basic design. The majority of rifles on the market use the same, or VERY similar actions and feed designs. Basic bolt action rifles are pretty simple to diagnose problems...since semi-auto 22lr's are blowback, fault diagnosis is quite simple here as well.
With the recent introduction of great finishes like duracoat, refinishing can be quite simple.
I think you made a great choice buying NEW for your first rifle. Learn how it works, where it wears, and what problems are common with rimfire rifles. Once you've got a little experience here, it makes buying used rifles MUCH easier. In the mean time, you've got a new rifle with customer service and a warrantee to back you up if any problems arise.
One this is for sure, if a seller is feeding you a story that seems to good to be true...more than often, it is!
Enjoy!!!!
