Is it common for tubes to outweigh the cost of the amp or preamp?

I appreciate all the feedback :)

I will chime in after work on the replies.

FYI the amp is a Woo Audio WA3. I've been using a Centrance Hifi-M8 for years with my HD800's and I've loved it. It was only recently when I picked up HD820's and plugged into my friends Bottlehead Crack that I realized I've been depriving myself. The OTL with those cans sounds so nice. Since I'm too lazy to build a kit amp I decided to go with the WA3 since it was similarly spec'd. I'm very impressed given the price.

And then... I googled "tube rolling". Whoops. So yeah, I got caught up in the hype. But if it's not hype and I do get a noticeable improvement then I'll be happy.

Thanks for the dialogue, folks!

300B tubes can often exceed the cost of the amp. 

Viva tubes

https://www.vivatubes.com/search.php?search_query=kt88&section=product

Thanks for that link.

Yes even better on some of the equivalent brand, but if your can prove your in the industry and join/login I think you'll find "some" are better from New Sensor. 

Cheers George

go with the flow man.

I always wondered if Uncle Fester on the Aadams Family could light up a tube like he could with a light bulb by putting it in his mouth. I expect he could but the visual effect would not be as apparent. sigh