Every speaker I’ve purchased the past 35 years has been used. Never had a problem and purchased much more expensive speakers than my budget could afford because I bought them used. I didn’t have $10k, what they sold for new, but I had 3k, and the seller ended up taking my ESL’s for an $1800 credit, so $1200 out of pocket for a $10k ESL was a no brainer. But no ESL I know of lasts 50 years! You’re lucky to get 20 years out of an ESL.
And word to the wise: I’d only ship speakers via ground freight. Shipped and secured on their own pallet. Will cost you a bit more than FedEx or UPS, but worth the peace of mind not being destroyed in transit!