I bought my MC501s 15 years ago used for $3,000 eaxh. They have driven my 3.6Maggies for that entire time. I could sell them tomorrow for what I paid. I found a recent sale on eBay for $3,000.
The sound is still amazing! Do not fear selling if you change your mind. Buy what sounds best and know you will not get hurt don the road selling. They are not for all, but no other mainstream amp hikds its value like McIntosh.