New guy from Appleton, WI considering self storage

[David Bond]

My wife and I are new to real estate investing. We bought a lake home an hour from our main home 2 years ago. This past April we bought (10 years sooner than planned) a second home on our lake and rehabbed it over 2 months. We have had great success using it as a vacation rental. We are looking for our second home within 15 minutes of our lake to do this again. 

We are in the process of selling our main home and moving to the lake (mostly) full time and just commuting to work. I'm 46 and would like to retire from my day job within the next 10 years. Once we sell our home we will have some extra money to invest.

In selling our home, I am giving up a nice work shop. I planned to build a pole barn near our lake home at some point. In the meantime, we have two storage units with all of our stuff in it. It was IMPOSSIBLE to get storage units in our lake area. This got me thinking.

I found a commercial lot that has a pole building on it that I think would work well to build the storage units on. It's been on the market for 9 months. 

I think I am ready to put in an offer. I assume I will need to get a commercial loan, though I would like to discuss seller financing with the seller. How do I do that through the realtor? 

How do I determine the value of this property? It appears he is asking $30K less than he paid for it 5 years ago. The seller finalized his divorce weeks before he listed this for sale. 

I appreciate your guidance!

Dave