Most of the ones on eBay do not have the factory cartons.
Yes! I ebayed a non factory boxed (mc452) about 2 years ago. Arrived with broken glass. Make sure if you do this, it is insured. On quality, I bought a new mc2500 and used it for 27 years. It was like the day I purchased it when I sold the unit (with original boxes) and received a really good price. I never had to have it serviced. I have speakers that are difficult to drive, so I purchased the 601's. For me, I think the old 2500 had a slightly warmer tone than the new equipment.
Yes! I ebayed a non factory boxed (mc452) about 2 years ago. Arrived with broken glass. Make sure if you do this, it is insured. On quality, I bought a new mc2500 and used it for 27 years. It was like the day I purchased it when I sold the unit (with original boxes) and received a really good price. I never had to have it serviced. I have speakers that are difficult to drive, so I purchased the 601's. For me, I think the old 2500 had a slightly warmer tone than the new equipment.