Amazon with IPTEK has the Apasiri Indoor Scratch-Resistant Felt Cat House Cave for $25 - $13 off with coupon code OACPS3F8 (click here to activate) [Exp 5/31] = $12 with free shipping on $35+ or with Prime.

After coupon, Apasiri Indoor 2-Tier Felt Cat House Cave is $11, the Indoor Felt Cat House Cave with Fluffy Ball is $12, and the Outdoor Cat Shelter is $25.