Just a followup on this, I got the specs of my "non-ASTRO" tube, and they look pretty good, based on what I've read on the forum:
Resolution: 72 SNR: 33.4 EBI: 1.0 PC Sensitivity: 2,728 Lum gain: 66,891 Halo: 0.8 Blemishes: zone 3 - 8x8 (?)
I wrote these down as he said them over the phone, so I'm not 100% sure about the "8x8" for the blemish, or what that means - only that it's in zone 3.
I feel like this should be "good enough" and not worth the additional $800 - especially for my first foray into NV. I mostly wanted to pass this along in case anyone else is considering the same thing.