This allows a taxpayer to exclude up to $250,000 ($500,000 for certain taxpayers who file a joint return) of the gain from the sale (or exchange) of property owned and used as a principal residence for at least two of the five years before the sale. 

On the market for 25 days; possible outcome: seller financing , Lease-Option, or sale and purchase more through 1031 exchange.

In your situation I would also think about putting 1031 exchanges to use.

Unless you're asking if the buyer can use the 1031 exchange to purchase a property that they are currently renting and have an option to purchase. 

If you miss your window and haven't lived there 2 of the last 5 years (like if you choose to sell several years down the road) consider a 1031 exchange and you may be able to get out of the capital gains as well.

They would likely have the tax liability immediately if it's not primary residence, so spreading it out over years may be helpful if they're not doing a 1031 exchange into a new investment property. 

Our arrangement called for him to do the vast majority of the work in exchange for 50% of the profit at the end.

TIC you tend to have voting rights individually so if lots of investors can be a mess deciding on any problems that come up while owning the asset.There are also UPREIT'sIf you are worth 50 million exchanging 1.5 million into something and want go one of the 3 routes you lose control and exit timing then maybe not such a big deal.If you are worth 2 million and this 1031 - 1.5 million has made it to where you can retire off of the cash flow then giving up control and timing can be HUGE versus owning yourself directly.

So I would appreciate it if you could assist me with some input on how to reach out to professionals and offer my assistance in exchange for experience.I am in the Tampa Bay area.

But can they claim they own the improvement and want some rent credit or payment in exchange at the end of the lease?