Sheriff Auction bidding checks

[Joe Attard]

I successfully purchased a home through our county sheriff auction.  However, I am curious how the professional bidders have the ability to bid on multiple homes.  

In order to bid on a home in the auction, the process involves securing a cashiers check in the amount of the starting bid.  You dont know the starting bid price until 1 hr prior to auction, so run to the bank and get the check for that exact amount, return to court house and bid on that house.  (if i fail on this home, thats it.  I cant bid another home after that because all my funds were allocated for that check/bid)

I noticed some of the bidders that bought multiple homes, had stacks of checks.  (more than the number of homes being auctioned that day)  Aside from having a large bank roll to support this type of bidding, are there others ways to secure these checks?  Are these check adjustable on the fly?  Or, do they just make an agreement with a lender, get all the checks printed, then agree to only use $$?