Best Buy has swiped $50 off the price of Barnes & Noble’s Nook Color e-reader, dropping it to $199.99 ahead of B&N’s Monday press conference to show off its next-generation Nook gadgets.

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The price drop was touted in a tweet spied by Engadget and supports speculation that after Monday’s all-but-certain unveiling of a new Nook, B&N may leavethe original Nook Color on the market at this reduced price, as an additional weapon against rival Amazon’s $199 Kindle Fire tablet, which ships November 15. As of this writing, the Nook Color is still priced at $249 onB&N’s own site.

B&N has a tough nut to crack against Amazon and its intimidating cloud offerings in books, music, TV, and movies. And besides the content considerations, the Kindle Fire is a full-on tablet, running Google’s Androidoperating system and featuring access to apps in the Android Marketplace. The Nook Color provides no such access, though it can be rooted to run Android.

Still, the Nook Color has one thing on the Kindle Fire: memory–which, considering the size of video files, is not insignificant. Both B&N’s and Amazon’s devices have 8GB of built-in memory, but the Nook has a memory-expansion slot and the Kindle Fire doesn’t. Plus, Engadget reported earlier that the new high-end Nook–which it says will be called the Nook Tablet–will have 16GB of inbuilt storage.

A big question is how much B&N will ask for the new Nook device. CNET Reviews Executive Editor David Carnoy has written that the company is likely to announce a faster and more powerful Nook Color that would cost anywhere from $249 to $299. Amazon allegedly loses money on each Kindle Fire it sells at the $199 price point.

Industry watchers have their eyes on both B&N’s and Amazon’s devices to see how they fare as lower-cost–though less powerful and versatile–alternatives to Apple’s popular iPad 2 tablet, which carries a starting price of about $500