Also, is a buyer's agent recommended on this type of transaction?

What would be the reason?
I would strongly recommend a lawyer, in this situation. As soon as you own the house and are leasing it, you become liable and the party for all insurance matters. A lawyer is the one to look after your interests in this case.

Why would the builder lease back?

That's strange ... usually a lease-back is because the seller is living in the house and doesn't want to vacate before closing.

Why would the builder want to rent from you?

One scenario come to mind. Maybe the builder wants to use the house as a "model" or sales center and needs the cash flow now? That would be a good deal for the builder, but expose the buyer to some liability. I would expect a really good deal on the price to provide the builder with this convenience.

chispa,

You nailed it right on the head as far as the builder's motives. Also, getting a good deal is something I will keep in mind.

I appreciate everyones comments about the liability and having a lawyer.

This was not uncommon in some Arizona developments and may still be. One in particular had about 10 houses owned by various people/investors leased back to the builder for use as models. The houses were loaded with lots of options. Per the sales prices they weren't sold at discounts. I can't speak for the terms of the leases with the builder so possibly that was more favorable. It went ok for a few years until the builder went bankrupt with the downturn in the market. The houses were then leased traditionally. We leased one for the first year during a relocation. I would definitely have representation from a realtor and/or a lawyer.