I always wondered why they chose Vultures for ATR as those form part of the staple of things I like murderising with fixed weapons (a mix of a Viper mk3 and FdL/Mamba would certainly give me pause however).
That aside, this is interesting because killing one ATR wouldn't be too bad as far as time is concerned. However it's going to be a challenge given that first you need to make a solid lump of pig iron (shields being useless of course), specific to this activity. You need to get good at flying it with no comparable challenge to the ATR to practice on and those things do spawn in pairs.
I'm pretty sure than for less than something like around 10k it's going to be beaten in efficiency and risk than a lot of other activities, so that seems fair too.
Although I do recognise how high risk, high reward activities are generally viewed, but hey, maybe something similar to this will appear one day (optional, avoidable, but there for those who want to test their skills/luck)