Should I wait and gamble that they won’t sell so I can do a conventional loan to buy both? 

I see it as more of a gamble than an investment.  

Are there defining characteristics that stand out?

Real estate wholesaling can be a great way to make money but there are some things you should do first.Know Your Market (the part of the country even the side of your city will have unique characteristics and it is important to know them).

Should you decide to gamble on your crystal ball and you manage to achieve 100% occupancy with an average rent of $735 a unit, that puts your GRI @ $52,920.

I have one potential tenant who wants 3 out of the 4 offices and a few other possibilities lined up who might be interested in the 4th.Here are some factors to the decision:My ultimate goal is to buy and hold properties for a long period of time so that once they are paid off, this will be my retirement income (I'm currently 35).While I have a positive cashflow on my first property, I don't have a lot saved up at this point that I could put towards a downpayment for the second property.I talked to a banker who, based on my current finances, would finance 100% of the property, 5 or 10 year loan, 4.5%, amortized either 20 or 25 years.So...from my perspective that looks like $0 down other than closing costs, and tenants lined up who are interested in the office.One problem is that given the asking price, and what the monthly mortgage + operating costs would be, the rents for the 4 offices would be 20-25% higher than the market rate.The potential tenant who is interested in the 3 offices is willing to pay that because there are some unique characteristics that they are specifically looking for that would be hard to find somewhere else.Let's say that tenant is willing to sign a 5 year lease initially.

Home warranties are just like gambling... 

Schools (www.greatschools.org) Elementary:Middle school:High school:Employment characteristics (www.city-data.com/) Unemployment rate:Employment appears permanent/stable or temporary?

The best example in my family is my dad offered to guaranty some of his brothers gambling debts to some loan sharks.

These are people who share motivational characteristics of people ready to sell, but haven't yet done all the work they think they need to list property.