We just don't quite know how to approach it and to determine what would be a fair price (one example was his price was about 62K for the architectural plans, permits, labor, materials, demo)I was trying to find other articles online about these kinds of ventures, but didn't turn up anything; so I figured some of you fine folks might have some insight into this.

The seller is giving us his architectural/civil eng. plans and the history of his zoning approvals which have since expired.

I will provide all architectural services.

Architectural design?

I am Connecticut raised, received a degree in architecture at Wentworth Institute of Technology in Boston, Massachusetts, and have been living and working in architecture in Denver, Colorado for four years in June 2020 with experience in developer driven SFR, Duplex and Multifamily as well as custom single family residence design and project management.

The city or county can have their own code requirements for architectural style and design which can up cost per sq ft a lot.

I'd use at least $275/sf or prob $350 just to be safe.Your soft costs including the architectural is prob half of what it should be.

Thank you @Andrew Galambos, I updated the original post - my friend does give them the architectural drawings/plans, so they are able to make a bid from that.

The opportunity to be of value can come in many different ways, and we each have our own talents. i.e. architecture, networking, design, cold calling, and more vs some people work a lot of hours and only have the time to put money into the stock market and look to diversify but dont always know where to go, so the opportunity to build those relationships with people for the long term will always be the way to go in this business. 

@Jonathan Greene I do have architectural plans on what the potential is for a house there...just gotta find the buyer!