Don't understand Priceline Airfare bidding

[tmynatt]

This is for a roundtrip ticket BNA -> CUN departing August 5 returning August 11. I found on Delta.com a ticket for $217.20 base fare + $74.14 taxes/fees = $291.34 total.

So I go to Priceline just to experiment. I put in BNA -> CUN for same dates and supply a bid of $217.00 The next screen tells me that my airline taxes and fees will be $137.45 for a total of $354.45, what am I missing here? Shouldn't the taxes + fees on Priceline be the same as Delta.com with maybe a few extra dollars for Priceline profit?

So for me to potentially purchase a ticket via Priceline I have to bid with a base fare of $154 in order to come out with a total Priceline cost of $291...which is what I would pay if I just bought it directly from Delta.

What am I misunderstanding here?

I do appreciate your help.

[thereuare]

Not sure of the routing of the Delta tix, but your PRICELINE bid agrees to at least one stopover... once the plane lands, it incurrs additional fees/taxes imposed by the government and/or airport. These fees vary depending upon whether or a take-off or landing, as well as which airport, so that can account for the difference in taxes.

Please use these PRICELINE and HOTWIRE links to begin your travel purchases.