$1280 sounds about right for a C2D. If it was an i5 or i7, I'd expect at least $1400. The RAM adds almost no value at all, as a new 8GB kit is only about $40 or so.
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iMac 27" 3.4GHz Core i7, 20GB RAM, 256GB SSD, 1TB HDD • 27" LED Cinema Display
MacBook Pro 13" 2.8GHz Core i7, 16GB RAM, 120GB SSD
iPhone 5 32GB • iPad 2 WiFi + 3G 64GB
Mac mini 2.3GHz Core i5, 16GB RAM, 128GB SSD (XBMC)
Synology DS1512+ NAS • DX513 Expansion • 20TB