Overall, a Marlin would seem to fit your bill, and budget. Savage is also there, but the quality of the magazines Savage makes are poor, horrible, in fact. The Marlin magazines are a lot better made. Both seem to be pretty accurate, for the .22WMR, anyway.
I had a Ruger American, the SS version, and it developed extraction issues fairly quickly. I loved it's handling, light weight, compactness, everything but the sticky extraction. I got mad at it and gave it to a nephew.
No iron sights on the SS model, some of the other SKUs have iron sights.
Those are about the only boltguns in your price range that have open sights are those noted. You might be able to find a used CZ 455 with iron sights, but most that buy CZs usually keep them anyway.
