Ipolic is right. It will take some time. One of my devs is working on a highly flexible theme for our own use (making it that flexible eliminates every need to create another theme again) which is based on Limitless web toolkit and he has worked on it now for maybe two months (really uncertain about the actual time since he is also working on plugins and we don't follow up on hours when we do work for our own use). Our theme, which is actually three themes, covers the backend, customer and frontend.
So yes, Ipolic is right, at least depending on what you want to achieve. It will take time so you can ditch any dreams of getting a theme that is not "too expensive".
Besides, if the theme is based on Limitless, the cost for a development license of that alone is $1200, but sure, also our extensive statistics plugin also uses it (the graphs etc) so in our case we can spread the cost on several features, but for a developer just wanting to create and sell a theme it will be tough to get profitability with it.
(our theme is not for sale, most of what we do is for our own reseller based service)