Go with your gut but head shyness is one of the easier things I've had to
solve. The last two horses I bought were terribly head shy. One was
13 and the other 9. There's different techniques to solve it. What I
usually do is put my hand as high on the horse's neck as he will tolerate, let
it sit for a second, and (important) remove it 'before' the horse raises his
head or reacts negatively. Then say "goooood boy" or whatever, repeat,
repeat, repeat. Gradually going higher and higher on the neck until you
are behind the ears. (this could take minutes, hours, days, or
weeks) (I usually do a few minutes a day around feeding times if I
can) Then do the same thing touching the ears (this is usually where the
problem is). You can give little treats to make the process a fun thing
for the horse. If you live near me I can send my daughter over. She
is brilliant with curing a head shy horse. She also tames feral cats as a
hobby (interesting child). The important thing is patience (lots) and
persistence. If you decide to buy the horse be sure and have your vet
(during the pre-purchase exam) check the horse's mouth, head, ears, etc. for any
medical reason why the horse would be head shy. It would be worth sedating
the horse to make sure. Also be on the lookout for other behavioral
issues. There is a reason why the horse is head shy and it probably had to
do with someone "earing" him or hitting him somewhere on the head. If that
is what happened there's no telling what else has happened to the horse.
Pay particular attention to how the horse reacts to his feet being handled and
how he loads and unloads in a trailer. For some reason the horse's head,
feet, and trailering skills are the first to go with an impatient handler.