Fatal error: get_header() undefined

I like the theme a lot, and am considering the pro version, but I am concerned with the number of errors it throws.

The big one is the fatal error:
Call to undefined function get_header() in hathor/index.php on line 1

then missing files:
/hathor/js/jquery.min.map 404 (Not Found)

then when I disable the slider, a series of ‘not founds’ from carouFredSel and 500/undefined function errors in index.php lines 1147/1195

I really don’t want to buy a theme that comes with a bunch of errors I have to fix. What gives?