With much respect intended, sincerely, don't take this the wrong way because its meant to be friendly, not harsh.
Auctions flourish on the bids of those that know the least. The savvy that "know the most" bid on as many as 20 items and may win 2,3, 4 or none. I've literally bid on 20 items with 100 hours of research and forethought and won zero before because the auction went insane. In another example I bid on 16 items and won 8 for what I thought were very good values.
But at any rate, auctions are designed to be deceptive. Auction estimates are always, on the average, considerably lower than reality for the purpose of luring in bidders. About 5% of the time they get it wrong and scare away all the bidders in which case I'm the guy in the wings the second the auction closes with a low-ball offer on a lot that received zero bids.
But for your specific gun, lets work the math:
$1500 high-estimate = 120% actually hammer price on the average, so $1800.
Then add 17.5% hammer premium.
Then add 3% online internet bidder premium.
Then $21 for insurance
Then $7.50 for the box
Then $75 for the shipping
Then 3% for Credit Card Processing
Then add in the delay of 3-4 weeks they take to get it shipped.
You can be the proud owner of a mass produced gun, sight unseen, for $2340.68.
Everyone has a different psychology about money and auctions so I don't judge you or anyone else for their preferences. I personally can afford to bid on $40,000 worth of bargains in an attempt to spend $9000 on three guns that are a steal, but I cannot afford to spend $2340.68 on a mass manufactured, used, push feed firearm that I cannot see in person ahead of time. I make mistakes, and if I were to buy that gun for $2340 and there is anything wrong with it, it might cost $500 to cure and I might sell it for HALF of my total investment...I can't afford that. But buying $8000 guns for half price? Yeah, I can survive an oversight or latent defect and still survive the transaction without losing months of my discretionary income in a single swoop.
Add in the value of time to enter-bid-pay-process, the deal breaks down for me, but as you'll see by what prices are fetched at Auctions, it is worth a lot of people's time that love the auction experience.
A much higher condition example of the same firearm was posted above in this thread on GunBroker for $2000 "buy it now". For a lot less messing around with auctions, you could buy a similar gun this morning for 15% less than the likely final cost of the Poulin rifle.