Does Monopoly Follow Standard Auction Procedures?
If you can't bid more than once in an auction, then you would want to go last. But everyone can't do this.

The standard auction procedure is to sell to the highest bidder. So if someone tops your bid, you have the right to top their bid. Until one person runs out of money, or otherwise gives up bidding. Then the bank is supposed to give the property to the highest final bidder. This is in the interest of the seller, because they get the highest possible price.

If, however, you are using a "one bid" rule, then it should be a secret bid. Everyone writes down their bid on a piece of paper and exposes it simultaneously, so that no one has an advantage by knowing what others bid and reacting to it.