Morning Jay,
there is another gem to be abstracted from your "perspective"...Noobs, Do Not Buy Cheap Valve Gear!
As Jay points out EVERYTHING to do with high end valve audio is expensive*. The professionals buy valve preamps for a specific reason and I am sure, do not stuff everything though them! Most of the time they use mixer channels or top end AI pres. The noob really does not need a valve mic amp and certainly not a $100 one! Then, valves fail, both catastrophically and gradually over time. Without the test gear and the knowhow you have no idea how the performance of a valve pre has changed over a year or two. Past a certain "mincrap" point, solid state gear just does not shift specc' for decades, possibly centuries!
*One area would be power supply regulation which I am sure is used in the Tree. Even most very high end "domestic" valve hi-fi uses unregulated supplies and lets the performance wander where it will at the whim of the utility company. This is not good enough in a piece of professional gear where gains and levels must be stable day in, day out.
Regulating the supplies in a solid state mixer is relatively trivial..NOT so for valve supplies!
Dave.