Can't decide Premium vs free template

Hi everyone,
I’ve made 2 wordpress websites based on twentyten and twentyeleven themes. I used child themes for css and slight php modifications plus included some plugins and js to fit my needs. I don’t know much about programing, but I’m not newbie and I’m learning. Now I want to startup my own 3rd web for my video posts and I need good starter webtemplate. My website would be prefered for ipads and desktop screens (maybe~960px grid) so I think between fixed or responsive templates as mobile screens isn’t my priority. I could buy one of the premium responsive tepmlaptes with prepared widgets, menus, sidebars, user friendly administration, portfolio layouts, grid/list toggle with filters and infiniteScroll etc. However is it premium template or free I will be forced to modify it for my needs.
Premium templates are administration friendly and prepared to use it as it is; And most Free templates are naked so developer must add css and all extenssions on their own.
My Q: Should I purchase premium template and made a child theme for it to develope template as I want – and play maze with their CODE while I understand what is what; Or should I use any free starter template and build my own template on it with CODEX tuts. What about updates? If I purchase premium template and will work on child theme then updates will be made automatically by developers. And If I made my own template based on free templates, how should I update my theme in the future to work hand in hand with new technologies, wordpress updates etc. I want to create nice and easy to use website for my readers, I can spend some time on coding it, but I would like to have support behind.
Whtat do you think? Mods for Premium or Build my own on starter template (if so, what starter template u suggest)?