Limited Edition TASCAM 424 Master High Bias Type II Cobalt Cassette - Are They Worth It?

So, I've been playing around with my cassette Portastudio for about 4 months now and I've been fine tuning the recording process.  However, I've been recording over old cassettes that are at least 7 to 8 years old.  I honestly didn't hear too much of a decay in the sound, but I recently saw that TASCAM, the company that made the Portastudio, decided to reissue a special high bias Cobalt tape designed especially for the Portastudio.  They are kinda expensive at $34.99 each, but I figured, why not try them out and besides they look pretty cool!  I finally got them and I must say, they do sound pretty damn good!  So good in fact, I can really tell my drum machine is an old cellphone!  I might have to upgrade my drum machine to something like an Alesis SR-16!