Question on Replacing Faucets

I am building with a builder and just had my plumbing selections meeting. They want to charge me $100-150 more per faucet than buying online. So i was considering having them just put in the cheap stuff (already in contract) and replace them myself. A couple quesitons:
1. What do I need to specify in order for my replacment faucets to fit. (e.g. If i have a single hole pull-down kitchen faucet with knob attached, just get a cheap version or if I have a 3 hole 8" center lav faucet just make sure the cheap one is likewise)

2. How difficult is replacing faucets, I've never done it before.

3. Anything else I need to consider
thanks

It depends on the actual installation. If the plumber uses a method of supply that makes change easy or, not.

Can't you simply renegotiate with your builder, select the other faucets that you want, and have the builder (sub) install them to begin with?
I can't imagine that being that big of a deal.
Mike

faucets

If they are furnishing them they will also be more expensive that if YOU went to Home Depot and bought them. You don't expect them to sell them to you at their cost do you? It doesn't work that way. If he furnishes them he has to deal with them leaking, having missing or defective parts. If you save money and buy them then YOU are responsible for all that as a bonus for saving money. Most plumbers prefer that you buy them, so they do not have to deal with dripping faucets, discolored finishes, etc.

Mike
I can look into it. The builder makes you use their sub, who marks up any upgraded faucet. For example, kitchen faucet I like I can get for $330 online. They are charging me $480 upgrade + deduction of standard faucet (roughly $50) or $530 for same faucet. they claim it's installed price (although installation is already included for standard faucet) plus their warranty, plus mark up of course. Don't know if I can negotiate the final differnce in price for the upgrades, but can try. Pretty much pigeon holed into this scenario. thanks