You need basic flying, however 6200g is the price of the full package, meaning regular flying + epic flying, if you want to raid Karazhan, you need to pay up at least 900g for regular flying.
I also want to point out that you couldn't farm Netherwing rep without epic flying, because the quest to actually go beyond Neutral with them requires epic flying.
https://wowpedia.fandom.com/wiki/Blo...the_Netherwing
Furthermore, this isn't about "being able to get where you want", you farm a lot faster with epic flying, thus make more gold per hour.