We would like to inquire if you could provide the 'wallet' feature at your marketplace where we would pay you upfront but would be able to spend from that by consulting from freelancers as and whenever we would need them in the future.
you have a similar feature if you sign up and use the mentoring services on Startups.com.
I am also a mentor there and I have regular clients that pay a monthly fee for a bank of consulting hours.
I've successfully helped over 350 entrepreneurs, startups and businesses, and I would be happy to help you. After scheduling a call, please send me some background information so that I can prepare in advance - thus giving you maximum value for your money. Take a look at the great reviews I’ve received: https://clarity.fm/assafben-david