Yeah, I've had an email about them and to be honest I don't like them. I mean they don't look very exciting at all. However, it doesn't seem 21 years ago since their Big Brother label started or 21 years ago since the Go Let It Out single was released.
I think that the Oasis merchandise on their official website is usually really dull to be honest and I would never buy it. The only things I have bought off there are the 25th anniversary editions of Definitely Maybe and (What's The Story) Morning Glory?
Don't think I would pay £25 for a t-shirt in any circumstance though (not one I couldn't try on anyway).
In the early Pretty Green days (more than 10 years ago), I paid up to £60 for Egyptian cotton tees and I never regretted it, in fact I still wear them while other, cheaper tees I bought at a later date are already dumped.