Do you think there's a market for a high end rack?

[Ernie Mccracken]

u mean high-end PVC racks? i don't think your plans would be competing w/ ARS And Freedom Breeders. anyway i'm sure u can get sales. i'm sure u can find a niche esp. if u market it correctly, like how your $700 rack can save someone money and costs less over time if it;s not dependent on heated rooms (or reasonably room temp warm and comfy).

my question is how many thermostats would be needed to regulate your rack? 5 for the 5 built in radiant heat panels?

Yeah not competing with metal racks which are for housing the maximum number of animals inside a heated area. I think both of those products are very good, but really not for the hobbyist.