Agreed with your idea of $15,000. If it was mine, I'd ask that... but would be happy with offers around $13,000.
FWIW, I bought my 95 with 50K on it for $9,500. Stone stock. I felt happy with that price based on condition of the truck.
'01 Lightning #1910 [silver] - SOLD
'93 Notch [bright red] - SOLD
'95 Lightning #13 [black]- R.I.P.
'93 Notch [electric red] - SOLD