Welcome to motorbiking Rachtak, If you lack fundamental mechanical knowledge this could get expensive. The typical guy will usually spend anywhere from $200 - $400 and this will be because he does his own work. Now if you half guess your way through the making of a gas bike, it could turn out to be real time consuming. Most of the kits are moderately difficult even for a mechanical guy. The easiest of all kits to use is the rack mounted engines with the belt drive. This can be done in as little as a half hour and not a lot of mechanical ability is needed. I would look at those kits first if I had your lack of mechanical experience. The only draw back those kits cost around 650 bucks.