I bought two just like the one in bchgrl's link (except they don't have the bow) at CVS pharmacy for $9.99 back in November. I got one in pink and the other in blue -- they have the exact same paw print material. EDIT: After checking further they are a different size too (20X20X20) and cost $38.95 -- almost 4 times as much!
The ones I bought at CVS are called Portable Pet House from Pet Pad. I did a google search and found these for double the price at overstock.com:
Pet's Pad 'Fold & Go' Portable Pet House | Overstock.com Mine are just like these except the size is smaller at 17X16X17 instead of 18X18X20 for the Overstock.com ones. I think the larger size is worth more....not sure double though.
Ebay also has them in varying qualities and different prints.