Preface: Have taken SVT-II into local, well respected repair shop. It went into standby mode and wouldn't come out for several minutes, plus haven't been happy with the tone for a while. Needs a tune up and diagnosis. Shop looks it over, says, "needs a retube." Quotes me nearly $400 out the door for Svetlanas + labor + tax. Research online and talkbass regarding tube choices and such, find a lot of often conflicting info regarding brand qualities etc., but quickly note that shop is charging me full MSRP on tubes in a post-internet world. Technical Question: Are Svetlana 6550's going to satisfy me? Do I need something more boutique or am I just throwing money away? Shop sounded unimpressed with other brands. Groove Tubes was the only upsell they recommended (when I pushed) but quoted full MSRP for those which are more expensive. Ethical Question: Shop, when confronted by their higher than street price quote for retail parts offered to drop a few bucks off the bill, but is still ~30% higher than for me to order them myself online, which for a sextet of 6550's adds up pretty quick. Do I support the local business knowing they've got to make profit somewhere? Do I demand to purchase my own parts, and expect to suffer a corkage fee of sorts? Do I dare try doing the retube myself, and cut them down to simply the fee for the diagnosis? I want to take care of the small business owner, my amp, and my bank acccount. Which part gives? Mature answers appreciated.