She wants to keep it as a rental property and purchase a new OO property because her family is growing and she and her husband + kids need something bigger.She has been attempting to get pre-approved, but they won't even discuss it without 20-30% down, or that much in equity in the current home, which isn't going to happen. 

Ex 1 (Basing ROI off of initial investment): Say you need $65k down and after 30 years you end up w/ over $400k in equity and say $350k in profit...

Thats probably a little tighter than I would have expected given the size of the rehab he had to do (typically you can get bigger discounts when the units need more work).But at the end of the day, you can see where the numbers still work out and he's still going to come out ahead.If he bought 5 duplexes just like that one, he'd end up with roughly 500k in equity and roughly 70k or so of his initial 110k in capital.What what really complete the story/picture is after he refi's the current duplex, how much money will he be making off each side once they're both rented out (i.e. net income)?

Keep cash on hand.2) Buy with enough margin for a correction (in equity and cash flow, if it fits your strategy.)3) High-demand areas w/ people and jobs, reasonable commutes to employment that are a good value.

However, I know I can get a good rate on a personal loan for 30k(I have excellent credit), and then I do have 40k in equity in my current residence.

and update on this story that happen about 10 months ago...so, the tenants moved in, paying $1300 per month. they re-sanded the floors, painted....pool is gone.i am doing a refinancing on the loan (to get a lower APR), so i needed an appraisal.the appraisal today came at $210k.so, i got 90k in equity without doing anything to the house. that makes me pretty happy.

When you hit 20% in equity, either from paying down the loan...or from rising values, you could then get a new appraisal and apply for your PMI to be dropped.

My current property has about a 70% LTV and I have about $50k in equity.

That would be $140K in down payments on a conventional loan and $140K in equity.

Now have $60K to $65K in equity.