What are these in good condition going for?

Gunbroker finished auctions (use the advanced search function and search completed auctions) have sale prices from about $635-1200, depending on condition, variation and accessories.

There was a 20" barrel and a 24" barrel. IIRC, the 24" brought a premium over the 20".

Generally the 24" rifles are XTR grade checkered walnut while the 20" carbines are pedestrian grade and un-checkered.