Depends on the complexity of their template system and theme engine. I doubt that it's that big of a deal if you look at the majority of their existing themes t

Depends on the complexity of their template system and theme engine. I doubt that it's that big of a deal if you look at the majority of their existing themes the engine and capabilities of the site are extremely simple. There are plenty of sites/designers/companies out there that will turn any PSD into html/css for between $99 and $299 including ADA compliance and cross browser compatibilities.