Solve checkout bugs from my magento 2.2.0 website!

Hi, I need a magento 2 / js/ css bug fixer for my website, where i cannot checkout to the successpage, there are several errors on console in chrome when we try to debug, the order goes through, we are using amasty's checkout and delivery order, but the problem is not with them even if we disable it wont work, seems like default checkout has some problem i want some one solid to fix this big. quote reasonably according to the job. please answer the question in order to qualify for the job what is 100+18? budget $50 to $100