Help with the math please

[Michael Plante]

I purchased 6 lots total cost $200,000    I have $50,000 cash into it    A 30 year mortgage @ 4% balloon in 4 years 

I can sell off the largest lot for $225,000 BUT I would carry a note with $45,000 down @ 5% interest amortized over 30 years. Balloon in 5 years.     Closing costs for me would be $23,000    I would need to use that as well as $125,000 cash from me to pay off the current mortgage 

I would then have 5 lots left to put houses on 

so it looks like I would have $25,000 profit in the end plus the 5% and have 5 lots free and clear for free

I’ve never been great at figuring returns or what is the best way to do something so I’m looking for advice 

If I could do a wraparound/land contract that seems much better as I wouldn’t have to come up with any cash and would make 1% interest on the $175,000

BUT I don’t think buyer will go for that