I am hopeful I could under bid and get it at a good deal.I would like to put an offer in, but I don't have enough cash to pay the full amount at auction.

@Wai-Ming LauMost contractors will not give you an itemized bid while walking a property.

He says if I pay him full asking, he would provide me with the 20% down payment since we could avoid realtor fees, and make up the rest by paying full asking (he had it appraised), rather than accepting an offer under asking.

I've been in real estate since 2015 and currently offer accounting services to investors.

There's nothing better than getting an FHA or conventional offer accepted by an unsuspecting seller, knowing you will have plenty of opportunity to re negotiate once the appraisal comes back.

Happy to offer up some more insights if you're interested.

Admittedly I am new to this and I haven't written a creative offer before. 

It's like being a novelist and people write a review that they never read the book but don't like the genre (happened to me- better to understand that some people are negative and walk with your head high).

Focus on how to juice cash flow if possible (rent by the room, separating spaces, etc.) or decreasing expenses (assuming a loan, looking at new build incentives, aggressive offers w/ rate buy downs that work for you, etc.) 

Either they’re going to make a killing or they’re going to stiff you and walk away.