without significant investment,we cant hire someone to create own wallet.
Is the monthly charge you're thinking about? since you're going to make your own P2P exchange, why not also hire someone that will create it for you instead of taking the service through them if you're worried about it.
In the long run, you'll save more and there will be a cut-off expense if what you are expecting comes.
Is Bitgo is a payment processor? I can see its just an exchange and lending platform when I open their official site but never hears of it until now.
It's like a company that provides services as I've read their website.
https://www.bitgo.com/