Covershield via eBay offers the OxGord 64" Cat Tree Tower Condo in Brown/White, model no. PCT-468-BR-WH, for $49.95 with free shipping. That's the lowest total price we could find by $15. It measures 20" x 20" x 64" and includes hanging toys and sisal posts.
XpectMoreForLess via eBay offers the 55" Cat Tree Condo in Beige, Brown, or Navy Blue for $39.99 with free shipping. That's the lowest total price we could find by $3. It features a faux fur scratching surface with pressed wood backing.