Yes and no.

1. No based on the way you mentioned it.

2. Yes, but marking up the SPA to the valuation price, but have the SPA lawyer to not release the remaining money to the owner (owner must be agreeable too). Usually the money given to you will be in the form of a "rebate".

This is highly illegal though.

Are you sure that what the developers are doing are above water with the banks?

For some banks and developments, when the EF banks know about the rebate, the starting margin gets reduced.

I see your point, but not all this is above water. In addition, the EF banks have interest in the development, it can't fail because they probably had provided a bridging loan too, which need to be passed to the purchasers as mortgages.