A 13.3-14.0 hand large is virtually impossible to sell as a division large, at least at the AA or even the good single A shows. Previous posters have commented that 2 inches doesn't matter, but it actually seems to. Very, very few 14 hand larges can canter slowly around a 3 foot course and have enough scope to be successful. Sometimes it happens - like Time To Talk - but usually with a very good rider and then eventually the pony gets scared when another rider makes mistakes and taps out the scope too many times.
However, in the Children's large division, 14 hands is fine. A winning, easy, fancy Children's Large can sell for up to 35k (for the big winner). I would focus on making him easy as possible and market him as a children's large/large green (he would probably be fine as a large green, especially at the 2nd tier rated shows). But make your focus on him being easy and a great 2'6 large that could move the kid up to the large greens.
As far as pricing, it's impossible without seeing him and getting a feel for his overall quality and level of training. Do you have a video?