Pictures can tell us a lot. Here’s a self-help thread on the use of posting buttons. You can post externally hosted pictures with the IMG tag like this for example.
The market on Alpines has been up and down. With the practical modifications considered / the modified soft top / radiator mods / and later series engine. Depending on the perspective buyer those practical modifications can be considered value enhancing. Can we also consider the original Series 3 front suspension or Series V mod? Any original interior components (radio / clock / dash condition [presumably wood for GT])? Brightwork condition? Wheel type?
Have you been able to find a comparable car for sale to see what others have been asking? Series 3 being the shortest production model can be compared a little more closely to the other early finned models. Alpines ranging between "complete rough rust free" and "show winner" have been advertised anywhere between $2,500 to $20,000. From your description you should be on the higher end, but judging how much to ask initially is going to be a breakdown of individual condition items and buyer negotiation.
Anyone else care to weigh in on discussing considerations?
Sure you don’t want to sell me your Husky instead? Seriously, Husky’s are way cool!