I agree, tis quite expensive. Just think, the Kelly Reebok "SAMPLE" jacket with real leather sleeves and 75% wool body, only cost me roughly 29 bucks on ebay four years ago.
However, if the back of the coat- "Buffalo Bills" was somewhat smaller and was the real "Bills" name logo, I might be inclined to purchase. I bought some authentic jersey's over the past 20 years and now with the new "Oriental Authentic" jersey's i have saved a lot of money.
I haven't purchased one from the Bills Store or NFL.com since '02. I bought an authentic 2004 Jim Kelly 75th Anniversary w/35th Bills aniversary patches, Rob Johnson, Eric Moulds, Nate Clements and Willis McGahee. With that money I could buy two of those jackets I linked to.