4-5% is typical when buying and 9-10% is typical when selling.  

Save this post, because if you think you can find and manage Class C tenants from OOS, there's a VERY high chance you will end up being penny-wise, but dollar-foolish.Hopefully, you'll be able to recover from your mistakes & losses and won't have to sell at a loss.

This was one of the selling points for us.

If good it will sell in a day, Good luck 

We prefer to have tenants on yearly written leases, unless we are looking to sell the property or have other plans and may do extensions of 6 months and one day if tenants are planning to relocate, purchase a home, etc,  and cannot commit to a 12 month lease.

They are looking to sell and would be subject to FIRPTA tax. 

Would it be just as profitable to sell their building/land and not build?

Should we risk renting or just sell?

I design affordable custom websites for small businesses, my designs specifically focus on getting the highest Google PageSpeed scores possible (example) which boosts their ability to rank in search engines and making sure their site includes at least 2 content silo pages that rank for specific keywords (ie "sell my house in Atlanta, GA"). 

As a result, I received early notice he was looking to sell.