Even if the goat super or the judge doesn't check teeth, the packer that ends up with the animals will, and that will come back to you and your fair. It's a bad idea, and if there is a rule, which I'm sure there is, it would be morally wrong for you to take an animal over a year old. I would recommend getting a kid no older than 10 months at fair time. It really depends on genetics too. Talk to your breeder. Some grow faster/slower than others. I know breeders that have kids hit 100# at 6 months old, mine don't get there until 9-10 months. Ideally, you want them to hit their peak maturity at fair. If they get there before fair, they will handle stale. As for your max at fair, it's possible. I have sold to fairs with low max weights before. Usually it is an issue with the packer taking the goats after fair. Either way, you need to check on that and make sure you know all the rules. The buckling is nice. What would you want him for? Breeding or cut him for market? Lastly, if you want a goat now, yes....get a breeding doe or a doeling. You can show her now and for as long as you like.