Its funny how one little decision can have such an impact on your home, and the costs of building it. I think a lot of people don't really think about what other things will need to be changed by simply choosing a different sink, faucet or doorknobs than usual.
For example, I'll use my own experience to illustrate my point here. In my case I don't regret making the choices I did as that is what I wanted in my home... but this is something to think about if you are making a choice that may or may not be really that important to you. I chose to use square vessel sinks in my master bath. Vessel sinks are basically like a bowl that sits on top of the countertop. When using vessel sinks, you either need a faucet that will come up high enough from the counter to clear the sink, a facuet that mounts to the wall, or a single hole faucet that mounts to the sink itself. The problem is... all of these types of facuets cost significantly more. So, you end up paying more for the fancy sinks, then more for the faucet and possibly more for the plumbing to supply that facuet.
Something to think about as you decide on the materials you'll be using in your new home.