Those specs don't line up - something is off.
Not to mention a 15" MBP for $650 I'd have to see it and touch it. Sounds like a ship it deal that never comes.
Mid 2010 MBP 6.2 came with Dual core i5 and Intel graphics w/a secondary Nvidia 330M, so the specs aren't a total flag. Memory speed is 1066 though instead of the stated 1333 The price is a huge flag for me. That's a $8-$900 machine on the market in my area.
Introduced April 2010
Discontinued February 2011
Model Identifier MacBookPro6,2
Model Number A1286
Order Number MC371LL/A (2.4), MC372LL/A (2.53), MC373LL/A (2.66 GHz)
Initial Price $1,799 (2.4 GHz), $1,999 (2.53 GHz), $2,199 (2.66 GHz)
Support Status Supported
Case Precision aluminum unibody
Weight and Dimensions 5.6 lbs., 0.95" H x 14.35" W x 9.82" D
PROCESSOR
Processor Intel Core i5 or Core i7 (M 520, M 540, M 620, M 640) ("Arrandale")
Processor Speed 2.4, 2.53, 2.66, or 2.8 GHz
Architecture 64-bit
Number of Cores 2
Cache 3 MB shared (2.4, 2.53 GHz) 4 MB shared (2.66, 2.8 GHz) L3
System Bus Intel Direct Media Interface (DMI) at 2.5 GT/s
STORAGE AND MEDIA
Storage 320 or 500 GB (5400-rpm SATA), or 500 GB (7200-rpm SATA), or 128, 256, or 512 GB (SSD)
Media 8x Slot-loading SuperDrive (DVD±R DL/DVD±RW/CD-RW)
KEYBOARD AND TRACKPAD
Trackpad Multi-Touch trackpad
Keyboard Built-in full-size backlit keyboard with 78 (U.S.) or 79 (ISO) keys
Now, all that said? If it's real, you can touch it, and it is in great condition? It's a good deal. Put the $ you save into an SSD and it'll be a fine machine. It's essentially not too far off a current spec 13" yet *should* have a dedicated graphics card that the 13" doesn't have.