Well, the MAC's are certainly good stuff and the resale on them hold well through the decades. There are other good tube amps out there, too, you might consider. I had a MAC 275 in my system for while, which was a loaner, so after a while I had to begrudgingly give it back. I did love the sound, to be sure. All those tubes glowing red at night was pure sex appeal. (At least my audiophile friends thought so.)
I wouldn't worry about opening the unit up for repair. If the repair shop is certified MAC, you will have no problems. Heck, if it is a highly regarded tube repair shop, you won't have a problem.
I think the real question you need to ask yourself is "how" you listen. With good solid state, you can leave it on all day, while you are home or not, listening critically or not, even leave it on all night, it won't care, it will just keep playing. With tubes, well, they do care. They have a short lifespan compared to solid state. At some point, they will wear out, and you will spend a hundred or two to replace them. So, I just don't let the tubes run unless I am critically listening, or at least, in the same room with them. The rest of the time I use the solid state home theater to fill the house with sound and bring life to movies.
The last question you need to ask yourself, although it appears you already asked and answered, is whether you want to go down the tube path. Once you do, and you like what you find, you will then want a tube preamp, a tube CD player, a tube crossover (if you use one), heck you will probably want tubes in your cereal bowl in the mornings. :-) The tube gear will act like a giant backhoe working overtime in your wallet. If you don't like what you find, well, in that case tube gear holds resale well, if you bought good stuff to begin with.
As for buying used, well, it is just a smaller bucket on the backhoe....
I wouldn't worry about opening the unit up for repair. If the repair shop is certified MAC, you will have no problems. Heck, if it is a highly regarded tube repair shop, you won't have a problem.
I think the real question you need to ask yourself is "how" you listen. With good solid state, you can leave it on all day, while you are home or not, listening critically or not, even leave it on all night, it won't care, it will just keep playing. With tubes, well, they do care. They have a short lifespan compared to solid state. At some point, they will wear out, and you will spend a hundred or two to replace them. So, I just don't let the tubes run unless I am critically listening, or at least, in the same room with them. The rest of the time I use the solid state home theater to fill the house with sound and bring life to movies.
The last question you need to ask yourself, although it appears you already asked and answered, is whether you want to go down the tube path. Once you do, and you like what you find, you will then want a tube preamp, a tube CD player, a tube crossover (if you use one), heck you will probably want tubes in your cereal bowl in the mornings. :-) The tube gear will act like a giant backhoe working overtime in your wallet. If you don't like what you find, well, in that case tube gear holds resale well, if you bought good stuff to begin with.
As for buying used, well, it is just a smaller bucket on the backhoe....