First I would not supply the washer and dryer.

Agree to pay some money up front or possibly negotiate to supply the materials as the contractor will have to come out of pocket on these costs.

@Karl B.But she would say the warranty is void due to power issue that supply it.

Now they're hung up on water supply after finally getting approval for the home sites. 

Not every are of the country is experiencing the same conditions so some of this may apply to some markets and not others.Construction costs are all about supply and demand like most things in the economy.

Richmond is changing rapidly because we have a significant demand for housing without much increase in supply.

It is a completely separate system than the domestic water supply, which is not used for irrigation.

Also, mobile homes do require specific materials which may need to be bought at your local mobile home supply store.

They are old and though they still work, the city says they leak and will affect the water supply. 

These are all built on an expanding money supply, money to lend & money to borrow, money to invest and the belief that a stable dollar (slowly deflating based on a prescribed inflation rate) so that future returns can be guessed at and calculated.