The pro's of buying new.
You get the warm fuzzy feeling that your the first person to use them.
You get a warrenty,BFD

,warrenty's are just like extended service plans,sales hype.
So what if you blow a $40 tweeter,the savings from buying used will cover a dozen tweeters.
The con's of buying new.
You get bent directly over without so much as a reach around

,only about 30% of the actual cost of a new speaker system goes into manufacturing,the remaining 70% is all profit for the manufacturer & the dealer/salesman.
The pro's of buying used.
You save a fat wad of cash.
Using $1,000 USD as an example,take that $1,000 & see what kind of new speaker system you can get from a store/botique or hifi shop,now take the same $1,000 & go to Audiogon.com,look at used speaker systems in the $1,000 range,you'll end up with a speaker system that cost atleast $3,000 when new,the best part is that most audiophiles treat their speakers better than their wives & they are mint.
The con's of buying used.
You dont get a warrenty,again BFD

.
You dont get all warm & fuzzy feeling about being the first person to own them.
Never buy any speakers or gear brand new unless you buy bottom of the line crap that has a history of cheap build quality or a reputation of being unreliable.
BTW,the speakers in my main system cost over $10,000 when new,i picked them up in person after an extended demo for $2,500 & they are near mint,if i was to resell them they would sell for around $5,000.
Dont be afraid of buying used,find gear local to you,dont get in a big fat rush to buy the first thing you like,people selling used audiophile gear are usually selling to fund a bigger more expensive purchase,this means either they desperately need the cash from the sale to move on another item or they just want rid of the old stuff,either way buying used gear is a buyers market meant to be exploited.