Hi Lee
I like ur designs. I have recently brought a 4ft x 4ft wendy house to put my rabbit in, this is becoming more popular and sheds too. I would say if you can put steps or a ramp and a shelf in half way and a hatch to the outside so a run could be attached you would definably get a good rabbit market. as sheds cost around the same figure u are quoting and then people need to spend a while adding the shelf etc. the only other thing I can think of is you would need to use bunny safe paint or no paint inside. also the rspca have guidelines on rabbit accommodation its 6ft x 2 ft x 2ft i think for 2 small rabbits. bigger rabbits need more space, so the rspca guidelines might be a good thing to mention on ur site. also rabbit hutches are meant to be off the ground to keep them warmer so even in a shed type thing it could do with some legs.