"Dave, I just want you to know that I appreciate you always being there for me for those (wow, has it really been) 17 years!
I do know I can come to you for all of my equipment and accessory needs, and take your recommendations, and know that I will get a great product and a great price. That does save an incredible amount of time and frustration!
There are some times when I have shopped around, but even then I never get better service, and rarely, if ever, find better prices.
Thanks for all you do!"