Quote from @Jason Hatfield: @Jaycee Greene  they require a non refundable deposit and give 48hrs to see proof of funds I would suggest developing a relationship with an HML/PML that would give you a "guidance line" that would basically be a "pre-approval" for situations like this to present to the buyer/auction company.

Do you have a pre-approval or proof of funds ready?

Suggest you check in with him/her on this additional service as your attorney is already intimately familiar with the file and you can often give them pre-authorized amounts to settle on vs trying to squeeze all the blood from that turnip. 

I’ve been investing for almost 3 months now, and have just started cold calling my call list of pre foreclosures aka I don’t have any properties yet.

The modeling of this is actually pretty easy (see link: 42-unit proforma sample), but my model treats the pre-refi loan as I/O, but that can be updated based on your deal.

Acquiring pre-existing rental portfolios?

Make sure to research lenders, get pre-approved, and calculate your potential ROI before bidding. 

I have a window into the PRE REOs coming to me, and lately, that list is getting LONG.

Once converted to a rental, repairs and improvements may qualify as deductible expenses, but pre-conversion repairs typically do not.

NEVER borrow from a 401K, you are taking pre-taxed dollars and paying it back with after tax dollars, you do not get to return the loan with pre taxed dollars, in addition, some 401K plans do charge interest and maybe even fees, and lastly if you get laid off for some reason, it is a distribution with all the "fun consequences: tax at the last dollar rate, and if you are under 59.5 there is also the additional 10% penalty.Personally I like the HELOC, however you can also sell stocks and do tax harvesting there to offset gains if that is an option