About that "one mesa, one peavey, one engl" thing, that's the way you could do it in the USA, but here in Germany the prices are totally different.
Mesa is fucking expensive here and Diezel is way cheaper than in the USA, the Triple Recto and the VH4 or Herbert are in the same price range (2500-3000 Euros), the Roadking is around 3700 Euros.
The price list is something like that here (only prices for new amps, nothing used):
Mesa Boogie Roadking-3700Euros
Mesa Boogie Triple Rectifier-2700 Euros
Mesa Boogie Dual Rectifier-2600 Euros
Mesa Boogie Roadster-2700 Euros
Mesa Boogie Mark IV-2700 Euros
Diezel Herbert -3000Euros
Diezel VH4-2700 Euros
Diezel Einstein 100 Watts-1800 Euros
Diezel Einstein 50 Watts-1700 Euros
Soldano Slo100-3700 Euros
Soldano Avenger-2100 Euros
Engl E670 Special Edition-3000 Euros
Engl Invader 100-2100 Euros
Engl Blackmore-1200 Euros
Engl Fireball-1000 Euros
Krank Krankenstein-2000 Euros
Krank Revolution-1700 Euros
Framus Cobra-1700 Euros
Peavey JSX-1700 Euros
Peavey XXX-1500 Euros
Peavey 6505-1150 Euros
Marshall JVM 410-1500 Euros
I think this shows why only a few here are using Mesa Boogie amps and many guys are using Engls or Peaveys and a few Diezel because a Diezel Herbert, Mesa Boogie Dual Rectifier, Bogner Überschall or some Soldano amps are in the same price range.
When I am searching for stuff at ebay.com I see all those Mesa Boogie amps for about 1000 euros in great condition, you can get 1500-1800 Euros for an amp like that in Germany.
So the prices are not only the fault of Mr. Diezel and they're built very very well, the tone is only a matter of taste, the prices are so high in the USA because of taxes and stuff like that.