With all due respect erik-squires, you are exaggerating and misrepresenting the repairability of Esoteric transports. The complaints only have to do with certain older models, with the early generation X-03 being one of them. TAP can repair the model that the OP is considering, the K-03. They will also fix some older models like the DV-50. My suggestion is to contact TAP before buying a used model to make sure it can be serviced.
I bought a used UX-3pi which needed to be repaired right after I received it (it would not play hybrid SACD’s). This model is over 10 years old. TAP did the repair and treated me well. The price for parts is dirt cheap. For example, the laser mechanism was only $85. While their hourly labor rates are somewhat high, they did my repair in around two hours. I was able to drive to TAP’s facility. The OP might have to factor in the cost of packaging and shipping in assessing whether it would be worth it to buy a used player.
I bought a Square Trade warranty with my UX-3pi. Highly recommended if one is available for your purchase if you are going the used route. They covered the cost of the repair, no hassles, and would have paid for shipping too.
As for the sound, my 10 year old UX-3Pi is very good, and I can only imagine how much better the K-03 would sound. I owned 6 dac’s in the past 3 years. All current production. My Esoteric player sounds better, or at least as good, as most of the dac’s that I owned. Maybe not as good as my Mojo dac, but it’s a close call.