If you were to paint that, inside and out, and do a nice glossy job (but not black, there are too many black blazers out there already!) then you probably have a much more valuable truck. It also appears that you have some damage to the hood on the passenger side as it does not lay flat with the fender.
I would want to see many more pictures, such as the dash, door cards, seats, headliner, engine compartment, and underneath everywhere before I could say for sure.
As it stands and from what I can see, $1000 is the most I would offer you. However, I am the kind of guy that is looking for a clean, well maintained, and non modified truck. I would want to see all factory parts and so forth. If someone offered you $1800 and you were looking to sell, I'd say that was a good offer!