He's getting the tubes from the actual Importer. They are going to match the tubes for him.
This could be hit or miss.Buying from a reputable vendor that does their own matching,in my opinion,is a safer way to go.The bottom line is this...If you feel comfortable with your guy,it's your money,spend it as you see fit.I still think you should get to know your equipment and do your own maintenance.It's very rewarding and will save you a ton of money.Good luck.