As with most things, you're gonna get what you pay for. You don't give many specifics about what you are looking for, or can afford to spend, but I've seen some pretty good quality human-hair full wigs (16-18") for in the three to four hundred dollar range. If you care for them properly they will last you a lifetime. An alternative would be to check out the various sites on-line selling human hair ponytails from haircuts. E-bay would be a good place to start. Here are some links to various sites that may help you. The great thing about shopping online is that you don't have to walk into a brick and mortar wig store and try to explain to a clerk what you are looking for (and why). Here are some places to start your search. Enjoy it! 
(The first link has a Renaissance collection that is guaranteed to be 100% European hair)