SOME vendors jack up the prices at events b/c the people are a 'captive audience' and more likely to buy what's in front of them. Not all vendors, but an unscrupulous few.

Quality of product comes down to the individual product. Some vendors at highland games have all Scottish made products and are very high quality. MANY MORE vendors have Pakistan / China -made accessories which are generally a lower quality and have a much lower price.

Bottom line... you get what you pay for. If the price is low on something, there's probably a reason. While there are certainly exceptions to this rule, as a general guideline, it's a pretty good starting point.