Yeah, $50,000 seems a bit rich but when the bank looks at the equity in the existing properties they are seeing that the total loans are in a relative insecure position.
I would not recommend buying the property without a sound equity base in this case, seems to be moving to the realms of gambling to me.
I would focus on getting the other loans down over time by capital payments.
Yes, if he buys this one and property goes up it is a 'masterstroke ' but it looks like in this case the upside is possible but the downside is heavily loaded and could end badly.
On percentages the odds of a bad outcome are too low and not worth the overall risk.
I don't borrow to buy shares anymore and personally would not buy a property with less than 40% equity in the overall deal. May not make me rich but I don't fret at any time either.