you can only try and advertise, My neighbour has a p@h 6ft by 2ft double rabbit hutch for her guineas there about £150. The sides are made with t&g but the back has thin ply wood 6mm max and its always soaking wet on the insides shes really disappointed. Guinea pigs require a lot less height so maybe Guniea hutches would be cheaper. also I loved Croftys old Hammy cage it was ace and her hammy looked so happy and busy in it, if you've got the patients for smaller things then there is probably a great mark up to be made.