Is it more expensive than an average bed? If it is, would people buy it?
Yes it does have new function, but we used mechanics and gravity to power the function of the bed. It does not run on electricity, uses up 0% of your electric bills. It likely cost only 5-10% more expensive than a conventional bed.
As you can see, some of the materials have been taken out in replacement of the spring. Hence, the pricing of the bed won't be of much difference than the average kind of beds and maybe even cheaper.