Buying first apartment building at auction, how to fund

[Tony Maro]

A local "investor" has about 15 properties going up for auction in the next couple of weeks.  One of which is a 5 unit apartment building that I'm interested in.

Buying any decently priced real estate in my area is a rare occurance to begin with, and finding even a duplex for sale is a once every 5 years thing.  This may be the only chance I have to jump into a 5 unit for the next 10 years.

I currently have just SFH's and even though I've done a bit of reading on apartments I'm not even close to comfortable with figuring out what a building is worth, so I have that risk. I've guessed at the rents ($650 / mo conservative per unit) based on our local market, etc. I'm pretty sure I could push that to $800 to $900 with a little effort but the market here won't support more. Then again he might already be renting them at $900 for all I know or even doing it as a section-8.

So, my back-of-the-napkin approach says it's probably worth $300k to $350k at $3250 rents but since I've barely even scratched the surface on multifamily valuations and not even sure on the rents I'm terrified I'm wrong.

My cap at auction would probably be $250k. I've got $100k in cash, clearly not enough to win the auction, and I don't have time to set up a line of credit - which I probably wouldn't be able to do anyway given what I've recently borrowed on a personal level. The most I could probably get a personal unsecured loan for would be $40k and I don't have time to get a HELOC or for that matter have the equity in my primary since I just bought it this year. Top it off I'm sure I'll need a chunk of that $100k as reserves to handle maintenance and renovations.

Would you guys n gals suggest I attend the auction just to see what happens or should I be prepared to bid?  And if I'm going to bid any suggestions on how to deal with this?  

Do I need the cash in my bank account on auction day?  I have one friend I could approach about either partnering with me or making a hard money loan who might be able to make up the difference until I can mortgage it, but I also don't want to waste his time either and as I mentioned, I have low confidence in myself for this type of deal.  Is there a way to purchase at auction without having the cash in your account on auction day?

My alternative is to check out the other SFH's he's auctioning, I'm sure there's several of those that would be worth the investment and fall within in my cash budget, but part of me really wants to jump into multi-family.