most pet shops have it..
as far as i know
i know the curve - pet safari has it
just beside the small fur animals ....
i think there is where they keep all the fish ponds..... there
or the dog section
but i dont think it is cheap..
you can try other pet shop - they have it :)
but further add on to dog is my buddy - do dogs really want to go into the dog house? mostly dont hahaa..
because
i have friends who has the dog house
end up the dogs - sleeping right in the middle of the hot sun from 10am to afternoon....