I agree with Ikkie,
My company have just gone through this as we went up against a competitor that offer custom HTML. We won the contract based on the fact that cost was a deciding factor.
Forgetting the initial cost of the website design and build we where very up front with the client regarding changes that they would need to have done moving forward.
Ikkie is right, with a HTML Custom site, you will have to pay for all of the amends to the site moving forward which over time can begin to add up.
There are some great templates out their for Wordpress that you can really make your own. I personally recommend looking a the Genesis Framework and a few of the templates available.
Hope that helps,
Stefan