With owner financing I'd offer $250k as you're going to need some funding to do repairs and upgrade the apartments. 

Up to code Electrical and Plumbing.Smoke and Carbon Monoxide Detectors.Windows, ventilation schedule, and forms of egress from bedrooms.Things to be careful about: Sometimes they might make you upgrade the water service, bring up things to code, etc.  

Ignore them (recommended) 4. file a police report (this doesn't solve anything) 5. invite them in to see the upgrades They will get tired and move on with life.

Presumably this is a condo so your capex will be limited, but you'll still need to think about occasionally replacing appliances or furniture, or cosmetic upgrades as time marches on.Overall your margins on this are pretty slim - there's a lot of variables in STRs and while they can be amazing investments, you've got to pencil out things for the worst case scenario so you don't end up losing money.  

Upgrade accordingly. 

Gross profit margin tagested at 15 ro 20% PLUS up grade profits as buyers customize the homes.My wife and her team will be the listing agent so this will be roughly $50,000,000 in volume for her over a 2.5 to 3 year period..

I'm not saying go crazy on the amount of rehab that needs to be done but there are upgrades and repairs that don't require much experience to complete because there are so many pros who do them that scare other people away. 

Upgrade to a more-sure thing.

I have done small cosmetic upgrades over the past 2 years which has resulted in $500 extra in rent per month.

Along with some cosmetic upgrades, they should also help to rent the place out quickly.