Since we're talking investment-
HD 650- $291 (Senn Black Friday sale 2012)
Crack + Speedball (SB free from that site) $279
TS-5998 tube $65 (because I'm a boss)
Tung-sol 12AU7 tube $19 Ebay
Total $654. Wow when I break it down like that, that makes me exceptionally happy considering I haven't even felt the slighted itch of upgraditus in almost a year.
Food for thought
Valab 23 step ladder Attenuator $30
JFX Premium Metallized Polypropylene Film Capacitors 100uf 250v 2 x $32
JFX Premium Metallized Polypropylene Film Capacitors 2.2uf 250v 1 x $3
Russian K72P6 Teflon bypass capacitor (silver one) 0.056uf $3
The results are very much grin inducing.