Fair market value of a turntable/arm/cartidge?

I may sell my turntable and am not sure how you determine a fair price since the front end is essentially three items, the table, arm, and pickup? Bluebook doesn't have this info. As an example, if I was to sell my Oracle Delphi Mark IV, SME345 arm, and Grado Sonata cartridge, what would it be worth? Assuming the combo is worth 50% of original retail may not be accurate to the buyer or seller. Other than place the complete front end up for auction and let the market decide the relative price, is there another method? I assume there are many enthusiasts (like me) that don't buy via auction, preferring fixed pricing transactions. I feel like I should end this with "sincerely, I remain clueless" Opinions are most welcome, Jeff