The later Denver Redfields might be worth that asking price, but the earlier scopes from the 1960s are not as durable, as Iron85 pointed out. I own a passel of late Redfields from Denver, and for one in very good shape, you would have to spend north of $500 to get an equivalent among today's offerings. There are more than a few for sale with problems, however. There are a couple of companies out there that will work on them, though.
Another brand to keep an eye out for is the Pentax Lightseeker line. These were US-made Burris scopes manufactured to Pentax specifications. I have a couple of those, and would have more, but they are not as common. They are very bright scopes with good color transmission.