Not sure I understand the mega-bucks for the vintage WE300Bs when the Takatsukis are available now - new production with 12 month warranty. Fantastic build quality, robust and likely to outlive many owners.
I have not heard the vintage or re-issue WE300Bs, but an audio friend of mine has compared both against the TA300B and puts the TA300B ahead - better extension top and bottom while the WE300Bs tend to be very mid-range centric. A one trick pony, albeit a very, very well executed trick.
Mids perhaps a touch better on the vintage WE300Bs, but not much in it. Certainly not enough to justify the price, or the risk, with NOS (or used) tubes when new production Takatsukis are available with a warranty?
YMMV, but 10K for a pair of used WE300Bs seems mildly insane to me. That amount would purchase several pairs of TA300Bs - a lifetime supply.