Used but not brand new. That crappy used crt will break in 6 months maybe if even. And replacing the picture tubes mega expensive.
I'm sorry, but that's just not the case. We go that route for a lot of the ones we use for the Midwest Gaming Classic. I have ones that I've had running since 2001 with no problems, let alone the vintage CRT monitors from the 80's that I still use. And if a TV crt breaks down (which I have yet to have happen), as stated they're cheap enough to run down to the local thrift and get a new one.
We just got a new sony 55" hidef. The old crt 60 inch was broken. Shaky and fuzzy lines. Then all of a suden no picture only sound untill I gave it a good slap. Then 2 days later picture went dead again. The tubes only have so much life. It was at least 10 or 15 years old. So nothing lasts for ever.