I agree with ghostchicken. Do not be afraid. I'm the world's worst at hands-on diy and was reluctant to get a tube amp, especially one that required manual biasing, but pretty quickly, I found that the rare times I have to bias are ritualistic much like the process or routine I go through in turning on my amp and components. In my integrated amp, I've had two power tubes and several preamp tubes die. It's not a big deal and the problem is much easier to solve than going into the internal workings of the amp.

When one of those two power tubes blew, it took out the $1.00 fuse. Again, not a big deal.

Now, I have tubes in both my separate phono preamps and my cd player. Sometimes when I place an order for vinyl from music direct or some other place that carries tubes, I order an extra pair of 12AX7 preamp tubes so I can roll and I'm not caught without replacements. I have a pair of NOS preamp tubes that I run regularly and a few single nos I swap out in my Bellari phono stage (only has one tube), but most of the new production tubes are good, reliable and easy to find. For no particular reason other than I went through that phase, I don't search eBay for NOS tubes anymore, but it was fun when I did.