Is that for pretty much any amp across the board, or is there a cutoff somewhere? For example, would I notice a difference if I got a Skar audio amp vs a high priced one?
I think that is a generalization. Generally (ha-ha) speaking, you pay more, you get more to a point. I tend to categorize product in the following categories:
Garbage:
Decent:
Good:
Very Good:
Very, very good:
Exceptional:
Benchmark:
That said, I think that $800 DS18 Hooligans 3K (new) $599 refurbished) is in the upper tier, not the top, but upper tier and just like JL, you pay for it. I put the DS18 (and this particular JL) in the Very good category, The MMATs in the very very good category, the Focal FDP in the very very good category and the AC in the very good category. When looking for items, I categorize them in accordance with my scale, then look for the best deal on very good or very very good equipment. I am not in a position to get everything in the Very very good and exceptional category, just is not in the budget for me personally. The scale is subjective and arbitrary to a point, but establishing your own and sticking to it is a good way to get what you need within a specific budgetary goal.
The DS18 EXL line is also Korean, uses Korean boards w/quality SMD's and the main difference between the two (as advised from a friend who works for them) is the parts are not all Korean and the labor is done in China, thus the lower cost. I think there are a lot of good quality reasonable priced offerings from the likes of Recoil, Stinger, NVX, CT designs, etc. I have 3 different amp brands as I went for the best deal I could get on for the respective application. $225 for an open box AudioControl 4.300 (tweeters), $549 for an open box Focal FDP 4.600 (6.5" comps) and $499 (factory direct) for the DS18 (all Korean) Hooligan 3K (dual Focal 13" subs). When ready to buy, set your goal, your budget and get the best deal on the products that fill the need.
My father always told me growing up that it cost a little more to do things right but it's always expensive to do them cheap.