KT 88 by EAT vs 6550

I recently tried to exchange the 6550 Sylvania C om my Convergent JL2 with the new exceptional rated (product of the year on HIFI+) KT 88 Diamond by E.A.T. (euroaudioteam): The results is outstanding.... Much more clarity, openess and musicality... simply incredible!
Well they certainly should be incredible for $250 EACH (not matched pair)! It would cost me $2000 to retube my Classic 60 with these, that's more than I paid for it! Talk about your expontential increase in cost for a small improvement.
in my opinion this kt88 by EAT is worth every cent... the tube is the wrong part of the audio system to save money... it is like to buy a ferrari with a fiat motor...
my convergent jl2 now sounds better then every amp I heard... and my new eidolon diamond..... are really flying to the stars...
I recommand strongly this tube, also for audio research reference 600 amps..
ps Are you sure 250 usd/pair is the correct price?
I saw a website selling them for 90 pounds apiece. How much is that in dollars?
ouch. $250.00 for a tube is some big bucks...then again I think of what I have spent on interconnects....