Hi I think I can do it about your high border, may be a bit less, but anyway about high. I can do it with help of another person. It will consist of Linux license server code. Webpage your with login to adjust clients licenses expiration dates, and add new licenses. Some protection at server side and inside DLL. Also can add client cabinets with abilities of prolong and buy licenses, but it will cost much more at least twice. 25000-50000. Becouse need to connect payment system. If interested write me I will ask second man how much he will take for server part.
It is without backtests. Only expert and license server. Profitability of expert and backtest it is your probability.