Mark Levinson No. 27 Amplifier, buy or not?

The sweet spot is the 27.5. While these model offerings were stellar in their day, one must understand that Levinson used many over the top military grade components in the circuitry of these, which are now simply unobtanium. Roll the dice.....YMMV....   

If its been serviced then yes they still sound very nice and worth having.  The 27 is warmer sounding than the 27.5.  If it hasn'tbeen serviced or caps replaced then yes you're rolling the dice. 

Its amp that I would keep for life, I thought there were more ML lovers out there in this forum who knows more about it.  Spending 2k is one thing for the amp, finding parts like others have stated is probably near impossible. 

Pyramid in Texas services these.  I have a 27.5.  It's wonderful, i have no plans to part with it.  Used all sorts of preamps, tube and solid state sounds great with all.  I used to be concerned with service cost (yes it is expensive) but I would spend it in a heartbeat.  

What more do you need to know? You buy one, you listen, you like, you keep. If it hasnt been serviced by a reputable shop (not many left), the odds arent in your favor. If it has been serviced, who did the work? Been down the vintage amp rabbit hole many times. The common theme? Financially, like most things in this hobby,  you lose, unless you plan to be buried with it. Your resale market? This vintage  ML? Spotty at best. Trust me, I have a Model 26 pre and PLS226 Power supply, restored. Would probably have to find a buyer in the Far East to break even. We American Audiophiles? Tighter than bark on a tree!       

Do a google search on Pyramid Levinson musings.  they are authorized Levinson repair center.  They give comments on many Levinson pieces.  They will also talk with you and give you advice.   You will find many comments and opinion here. I took the plunge after researching.  Good Luck.