I think your price is very competitive given the somewhat-low mileage and documented service history. I would hold firm unless you're absolutely need to have it sold ASAP.
Do you have the stock wheels? Maybe that would help the sale. People generally shy away from aftermarket stuff right away.
Imola Red / Imola Red ///M5
E60 SSK, Dice iPod, Illuminated ZHP knob, MKIV, Euro Armrest, GT ExhaustDaily:
BCR Coilovers, 19x10 + 19x11 Rial Daytona Race, Michelin Pilot Super Sport
'04 E55 AMG Brilliant Silver on Anthracite
'96 318i Alpine White on Black
'01 330Ci Titanium Silver on Coral Red
'96 328i Jet Black on Black