Typical lifespan for a 5 channel power amp?

Hello All,

So last year I had a chance to get my hands on a Simaudio Moon Titan HT200 5 channel amp. It was listed for $5500 on Ebay. I threw out an offer of 3K cash never ever expecting to get it, yet they accepted (I was within driving distance and that was very intriguing for the seller to not have to ship this beast and we did it offline thereby saving the seller fees, etc). It had low hours and really is in pristine shape. I had wanted this amp since it first came out in early 2000. Don't get me wrong I am thrilled with this amp and love it. However I can't help but feel since it is quite a bit older, and I do use it every single day for music, tv watching, movies, how many more years does this thing have left? Would I be better selling now while it still is in full, pristine operating condition and getting something new like say an Earthquake Cinenova Grande or ATI 6005?

Any thoughts/advice greatly appreciated...