You can listen and enjoy the music before the tubes fully warm up and sound their best so don't let that possibly sway you away. Also, there are a number of quality tube suppliers out there so you don't have to rely upon the manufacturers supply. One of the benefits of tube equipment is being able to swap in (tube roll) different brands and equivalent tube types to tailor the sound as you like it. Here's a link to Brent Jesse's website (I don't work there) that if you scroll threw to different tube pages you can get a sense of variety of NOS tubes versus new production and his impressions on sound. There are other competent/quality tube sellers out there as well.
http://www.audiotubes.com/
http://www.audiotubes.com/