p38 dt trade in or sell

I have a very tidy m reg dt 157k on the clock in excellent condition but its time to go commercial ...a nissan nivara is on the cards but the question is wether to trade in or sell privatly .... shes supposedly chipped and has uprated intercooler and turbo (previos owner ) and has a new aschroft fitted gear box (manual) last month ..shes also got the late model flash alloys and the old ones as spares ...anyone got any ideas what I could expect on trade in ? ( nivara is 12k ) or anybody got a loving home for her...