[Tervuren]

I don't see it as an ethics issue at all. There are different models to sell product.

A race shop, offers the customer the advantage of being able to buy things all on the same bill.

Selling to a race shop, offers the producer the ability to sell multiple in one order, and not deal with individuals.

If race shops are not likely to buy that product from the producer in quantities above single units, you might run into manufacturers seeing little difference between dealing with the end user vs a shop.

Eithics comes into play, when say, a dealer takes the time to design an entire system for a job, and he never gets payed for that design work as the manufacturer stepped in and sold it direct.

So maybe its bad business practice for the industry, but I don't see it being an ethics issue as outlined in your post.