Buy tubes from Audio Research or not


I need to retube my amp and I'm having trouble deciding whether I should buy my tubes from Audio Research or buy them on the open market. If you have any experience with this I'd appreciate your help.
taters
The tubes are 6550 that have been matched and run for 24 hours. ARC matches the tubes and runs then for 48 hours. My guy buys the tubes right from the importer. He doesn't go threw a middleman. My guy can also get the tubes right from ARC but I'm going to have to pay 400.00 more. He says it's not worth spending 400.00 more and that if I did the sound would be the same. It sounds like the logical thing to do is let him get the tubes and Install them and save the 400.00.
Do you see anything wrong with this scenario?
Yes! If "your guy" only buys 8 tubes how can he get two matched quads, he doesn't have a big enough inventory to choose from. Is he supplying SED Winged C 6550's ?
Taters what about the (4) 6922 input and the (4) 6922 driver tubes? Are they still good? This appears to be the more difficult area of VT 100 Mkll tube replacement.
Samhar...I believe Taters has the VT100MkIII which is easier to bias than Mk I and II (see Davemitchell's comment above).

Taters...I agree with Samhar that you should be a bit more careful that this tech guy is going to put in appropriate tubes. There is nothing wrong with getting him to do it as long as you know he is getting 2 sets of matched quads or a matched octet of 6550s. I would also agree that yo want to make sure the 6922 input/driver tubes (especially the driver tubes) are up to spec. So I would tell the Tech guy that you want to be present when he retubes your amp so you can learn how to check and maintain it going forward. And if he says ok, then you want to make sure that he tests the tubes in front of you and explains toyou that the tubes are testing well and that he then shows you how to check bias measurements and to adjust bias after retubing the unit. If he is ok with that, you then can personally verify that things are being done to spec and you are learning how to do it for yourself going forward. My 2c worth
Just a couple of comments about retubing a Mkiii. It uses 6H30 tubes not 6922's. The 6H30's don't need to be adjusted like the 6922's from the Mki and Mkii's, you only need to bias the 6550's. If you have a multimeter and the Audio Research bias tool(looks like a screwdriver with a small blade and wooden handle) its a straight forward process. Although i install my own tubes and bias my VT100 Mkiii, I still buy my tubes from ARC. They are more expensive but if a tube fails, Arc has a 90 day warranty period and would cover appropriate repairs. Its just a risk decision on how much you trust your local Tech or yourself.