There may be more than advert cover collectors bidding. You might have one of us postmark collectors bidding too. (I'm neither a bidder nor the seller)
Pre 1900 postmarks were typically collected by cutting the postmark to 2 X 4 inches or even cutting out just the date stamp. If the postmark or cancel type is scarce, $4 to $6 a cover is not unusual.
The description states the "Ira VT" backstamp is a DPO and has an RF5. That's a gauge of the postmark's scarcity. A 5 is high so it would command a premium to a serious VT postmark collector.
The fact that they are nice advert covers with clean strikes to boot is just gravy.

Dan
