More or less all zillow's algorithm takes into account is location, sq ft, year built, bed & bath counts correct?

Bedroom and bathroom count?

If you have funds and have communicated with the firm (after you’re the closed, winning bidder they’re usually happy to take your call), you can technically pay at any point that is convenient to them and you prior to that date and I know they have moved dates back in some circumstances before but don’t count on that. 

@Chris Gaston Regardless of unit count ... it would be good to get the current rent roll and the profit and loss statement.

@Drew Wa depending on the tenor of the installment sale, IRS does have a minimum interest requirement - ie. if you claim a 0% interest rate, the IRS has a table with what the minimum interest rate should be on an installment sale of that tenor, and you will be paying taxes on the deemed interest.On the capital gains front, I am not 100% certain, but it would make sense that any installment gains received in the first 12 months of your purchase of the property would count as short term gains and anything after 12 months would be long term, again, not certain as to this point.

As a buy and hold I never count on it; having said that I have made as much money from appreciation as I have from collecting rent.Some folks use a 3% number, if that helps.

Same if you buy a house and put 40% down.Other than that, equity in other real estate does not count for a whole lot.

If the finished product you end up with is very similar in square foot, bed/bath count, fit and finish, and you get an appraised value of at least $100k, you should be able to get $70k, I have a few banks that could lend to you if your personal credit is good too.  

At the same time, 1 to 4 units are still counted as residential for lending.

@Dayton Komarek definitely an apartment, I don’t know if you would like to get fixated in one spot for 30+ years, not counting all the overheads that will require to maintain that liability.