We did a lot of the work on this house ourselves to get it sale ready but it was brutal, took longer than we expected to do everything and the end product wasn't as good on half of what we did because of time constraints. 

Way to jump in, half the battle in my opinion is getting into the game. 

It took me a year and a half before I even got an offer accepted on a property.

Either they are clueless (I’ve seen this) where they give a “price” but it’s an assignment where they don’t want you to see the contract.....sort of a stupid way of doing a half *** double close.  

A standard inspection should cost around $500-600, investor reports should be around half that cost.Make sure you only do inspections on something you’re serious about buying otherwise costs add up real quick.

They were on the same block, not 5.5 miles away.

In looking over the disclosures, it says there's a landfill 2.5 miles away (west of property) and wastewater treatment facility 3 miles away (northwest of property). 

Although only HALF the property is vacant, it happens TWICE as often.

If we go 50/50, should our partner pay us half of what my husband would charge for labor and materials?

Have you noticed the countless case studies of six-figure earners who reach FI much slower than people making half as much?