How to build an (almost) StackOverflow clone with minimal effort?

I have startup idea (http://ift.tt/20dC36p) that will be a Q & A website where people that ask question can pledge to give a certain amount of money that will be given to the author of the best question. I'm learning Javascript and already am pretty fluent with HTML/CSSS. However, I do not know Python and I'm quite a newby at building web product. I identified this script on GitHub that would provide me with 90 % of the features I need : http://ift.tt/1fOVYSB

However, I was wondering if it would be easy to add the payment/contest feature mentioned above to this script and change the UI with CSS. If I subcontract this on Upwork, how many hours do you think it might take? Do you think I could do it myself? Thanks 1000 times in advance!