The balancer is the easy thing to find. There are zillions of good, accurate computer balancers in every city.
The challenge is lining everything else up as outlined by 400E.
This includes: the correct weight for the rim, someone willing to do a DYNAMIC balance with weights on 2 planes, an operator with an IQ above 70 AND the attitude and determination to see that is done correctly giving the customer what they paid for. This is a tall order.
I agree about the dealer to a point. You are more likely to get all the above conditions met at the dealer, but not guaranteed. In fact there are a few dealers that provide a poorer attitude than the kid at the tire store.
Balancing a wheel properly with the proper materials is not difficult. I could take anyone with an IQ above 70 and teach them how to do it on my Coats 1001 in a half hour. That leaves the attitude problem. Attitude is everything. I have a piece of artwork that my daughter gave me when she was in the fourth grade. It says "It's all got to do with the Attitude." This is incorrect grammar but a very meaningfull statement.
Have a great day,