I am seriously considering coming over to the dark side. I’m an oboist by trade, but have been playing flute and whistles for a few years now. I have my eye on a couple used practice or half sets for sale, but the difference in cost to new is only a couple hundred dollars. Should the original (2) year old reeds last a while, or should I expect to have to replace them? With that said, for the cost of new reeds I could nearly buy a new set? 
hi new piper,welcome to the pleasure dome.i have been teaching an oboe player to play the pipes recently and i was astounded to hear how many reeds he went through.because the oboe etc, is a wet blown reed the life span of them is very short.however,the uilleann reed is dry blown and if made correctly is very stable and durable depending on the cane which is always the variable.you should have no worries about the cost of your reeds compared to the oboe,i know of pipers who have had a chanter reed in for decades.if you get a reed that will play for a year or two you are quids in.fiddlers pay thirty or forty pounds for a set of strings and change them regularly while the parsimonious pipers moan at shelling out for a reed every few years or so.your reed bill will be far less if you become an uilleann piper and feck all if you learn to make your own reeds.having said this please beware of what pipes you buy.buy from a reputable maker,the stuff that you get on ebay etc.that claims to be newly made practice sets from the east are invariably a crock of doo doo as are the half sets and full sets.i have known many an aspiring piper who have been heartbroken by buying rubbish sets that even an experienced and dedicated restorer can do nothing with,you can not make a silk purse out of a sows ear.caveat emptor.good luck ,be careful.all the best,allan moller.
(I make my oboe reeds from stock tube cane - takes a mountain of time and effort to make a finished reed that plays well, and then they last about a week. Nuts.)
No worries about junky pipes. We have two good makers not too far from me in the North East USA that I’m considering. I was just curious about comparing used set prices to new ones, if I have to replace the reeds as well. Adding the price of a couple new reeds makes the old set almost the same cost as the new.
The main consideration with used vs new is often time as much as anything else. It is usually faster to get a used instrument than a new one since just about everyone worth buying from has a waiting list.
Kevin
If the reeds in the old set are working, they could last for a long time. Same goes for the new set, for that matter. Often it’s a struggle to get a set properly reeded, but once it’s going a good reed could last for a many years. My chanter reed turns 32 this Spring.
.. and if you can make oboe reeds you’ve got a head start! Just DON’T put the chanter reed in your mouth. Like, ever. Sucking on the staple end to test the crow is okay, but wetting the head (the cane end) is a bad idea (yes, I speak from experience 
).
Regardless of whether you buy a new or a used set, beware of the change in temperature and humidity when the set is shipped to you. New or old, reeds are delicate and react to changes in temperature and humidity.
A reed that played and sounded great in the maker’s/seller’s home may sound entirely different in your living room. Also, new reeds are just as prone as old reeds to collapse or crack because the change in climate is too sudden.
A well-made reed can last many years, provided you look after it. Don’t expose it to sudden changes in temp/humidity and don’t mess with it unnecessarily.