sell third house this time dump half the profit into SnP 500 index fund, other half builds fourth house... repeat until satisfied with stock portfolio, retire at 50option C) Aggressive model: sell house for $600k just keep carrying my primary mortgage which is $2900/month and dump the money into 2 properties and build 2 house at once that would each be worth $600k...?  

Instead they go about it a** backwards and add more red tape and more complications costing the city and it's residents more money

Conventional, after two hard money people fell through How did you add value to the deal?

He likely needs to stay where he is, save up money for a downpayment on his own, and buy when HE is ready.He's not ready. 

I’ve been in this situation and with a growing portfolio and expenses, it’s hard to put money aside for two mortgage payments.At Sid Was Here, my management company, we’ve always offered to let guests pay into the future for longer stays.

Then use a small chunk as "learning money" so if you don't lose it all, it won't be detrimental.

Save that down payment money you mentioned or go for a multi family at a higher price than the single but have rental income. 

He must have spent gobs of time and money every year maintaining the books and the structure. 

Once Apartments.com is going the money comes without much thought. i check on the first to see that the transaction has initiated then again on the eighth to see that the money deposited.

The only way I can access is money is through my primary residence and doing a HELOC.