a few years ago I was asked to quote for some newbuilds, which tbh I don't do, however nobody was interested so it seems they were trying to get quotes off anyone. They were building an estate of about a thousand homes of various sizes, however due to the market at the time they were planning to build say 50 properties and when they'd sold build another 50 and so on.
However this is where it got interesting, the idea was they'd give you the contract for the lot, but you only got paid after doing 500, and obviously you couldn't alter the price. Now if it took 2 years to build and sell them all then prices would naturally increase, and thereby you'd end up taking a hit.
Not surprisingly nobody would take it on, so they had a rethink and came up with a different plan, they'd pay you in blocks of 50,however in the time it took to complete them amdt 3 came in requiring metal CU's,and I remember there being a big argument as the original quote was to use plastic ones and the main contractor didn't want to pay the extra, I don't know how it all ended, but I do know they still haven't built all the houses yet.
I often wondered how they expected anyone to be able to lay out for wages and materials for 500 houses then wait an unknown length of time to get paid.