Without knowing what they mean by central controller, I cannot even look up the servicer price. Did they say the digital control board, the dlp light engine and controller, etc.
Most of the digital boards run between $240 and $400, the dlp light engine and controller runs $1800. These are not including shipping or any markup at all. The lamp alone is around $300.
I would not be suprised to see a total repair bill in the $500-$600 range which is typical since Samsung is board level replacement. Looks like it is about a $2000-$2500 at retail set right now.
How far out of warranty and where was it purchased? You might be able to get some minimal part cost help from Samsung if you call them and you did not buy it from Sears.