If a comparable model is available, Best Buy will give you that. A few weeks ago I had a guy with a junked out Samsung UN55C7000, and I gave him a UN55ES7500 as a replacement. He didn't have to pay anything.
BB replacements are supposed to go feature-for-feature when trying to find you a replacement. I don't know of any EW that gives you a replacement based on how much you paid for your original set.
If there's no longer anything comparable to the television you had (counting in-store and BestBuy.com selection), you're supposed to be issued a gift card equal to the original amount you paid.
ht Panasonic TC-P60ZT60, Monitor Audio: Silver RX6, RX Centre, Radius 90HD; Martinlogan Dynamo 700, Marantz SR5006, PS3, Oppo BDP-103D
2ch Marantz PM8004, Sony BDP-S1000ES, JVC T-X3 tuner, Monitor Audio Silver RX1, REL T3, Apple TV, Peachtree Audio DAC•iT
lr Panasonic 50ST60, Sony BDP-S5100