I randomly got looking at rack power amps for no reason what so ever yesterday and now I'm wondering, what's the point, they are so expensive, if someone wanted a 100w 6L6 power amp why don't they spend £300 on a 100w valveking head instead and save themselves a small fortune
is my sense of logic wrong? there can't be a couple of hundred quids worth of difference in tone from a power amp to justify the additional cost?
Several reasons for this:
1) The power amp contains all the expensive bits in an amp.
2) As stated above economy of scale. This has a huge effect on price. Look at the price of new cars compared to a high end guitar.
3) Rack gear is really aimed at the professional market, so a higher standard of build is required. Pro equipment needs to be more reliable than "domestic" amps.
4) A consequence of 3) is that the individual parts are more expensive. Transformers were mentioned. These (should be!) the most expensive part in a valve amp. Compare the size of the transformers in a Peavey amp with other brands on the market and you will see where money has been saved. Even items like the rack enclosure will cost more than the amp sleeve and chassis on the Peavey. This is beacuse it has to support the weight of the amp when in the rack.
I always it ironic that on this forum, where the benefits of spending £190 on a pair of humbuckers is seen as worthwhile (and don't get me wrong here I have always been very impressed with all the BKPs I have tried and often recommend them), that people object to paying more than £300 for a whole amp!!
Transformers contain more expensive parts than pickups, are more difficult to wind, have to pass very strict safety standards (which costs more money) and have a very significant influence not just on tone but on the reliability of you equipment.