core 2 e6750 @3.7Ghz
P5n-e Sli motherboard
what i want to know is it i sell this for round R3000 (which is round about what i paid for it 1.5 years ago) am i going to
Not sure what the market prices are for those parts now. Price them yourself - see what they would cost to replace now. Thats probably what they're worth.
It's unlikely it will fetch the same price you paid 18 months ago. Then a new E6750 went for about $200. Overclocking the E6750 to 3.7Ghz will not have increased its resale value.
Today you could pick up a good used E6750 for around $50. And a brand new E5300 2.6GHz for around $70.
My opinion is you won't see a good return on the price you pay for the upgrade.