Heya,
Yeap. Because I'm factoring that he'll end up buying a second headphone, meeting that "price difference" when he realizes they don't sound great for everything, and are really meh when it comes to music that involves bass. Maybe I'm wrong, maybe he will love the anemic signature of the AD700 (and even the AD900). But pop and rock with no bottom end? Meh. HD598 would be much more thrilling with some bass. So yea, factored.
HD598, you buy one headphone.
AD700, you will buy other headphones.
Note, many are likely to buy more headphones anyways.
When it comes to throwing down money on an expensive headphone, you might as well get the most you can for your money. Frankly, the AD700 is not the most. Not even close. I don't get the hype around that headphone. If someone was really on a budget and cost mattered, they'd get a headphone that was if nothing more able to accomplish a good sound in all music types. AD700 isn't it.
And if we're talking price factoring, the Samson SR850 (Superlux HD668B) is better than the AD700. Has bass. And is less expensive.
Very best,