How much is a 1783 El Cazador shipwreck Spanish 1/2 Real (Reale) in
ANACS cerified Prime Select condition worth?

I strongly suggest going to   

http://www.coinsite.com/

and look through the archives of the Coin Doctor.  Note the level of
detail people ask, and the photos they often provide.  If you do your
homework and know how to ask the question with the proper level of
thoroughness, the Coin Doc will give you the answer you are looking
for.  Please note the the level of detail you have included above is
not sufficient.  Good luck!!  Big Blue