Door County vacation rental condos -- why so cheap?

[TD Smith]

Having just spent a lovely weekend in Door County, Wisconsin and coming from the (comparatively -- okay, absolutely) pricier vacation spot of Telluride, CO, I'm wondering why such a charming set of waterside villages within driving distance of Chicago, Milwaukee, etc., should be so inexpensive! 2 bed/2 ba condos, well-maintained with apparently good rental histories, are going for $75-125k! (Add a zero or two for Telluride.)