Could you go ahead and register the foal here : Chincoteague and then vet test, here? Vet

Doing so, will help people let you know what the foal's value is worth, as sometimes genes and stars? Play into a selling price too.

Thank you for that advice! I have just done so now 

While, I cannot offer a price suggestion for you, but any wild you capture and wish to sell? It's always recommended to register them, into their proper Breed Registry and get them into the Vets, for a gene testing, as an adult, it would help to test out their personalities too. 

Some horses, can have genes, people are looking for and it can help make or break a price asking point.

Unfortunately, as it is a foal, you cannot test it in Foal Predictor, using premium currency of Ingots. Sometimes, adult horses, can carry the ability, to be a dapple carrier and can help give a better pricing too.