Just hatched a 15A/12D/13S Aron, reaching 191 candy.

Aggron isn't great against Jynx. You can beat Jynx with a few Flareon mixed with something tankier like Entei, Moltress, Ttar and Metagross.

Aggron is an acceptable tank against Jynx, anchoring a team of say 5 Flareon, which has a significant survivability problem, but I would not invest stardust into a hatch with less than 100% IVs. You're better off looking for a level 35 Aron during partly cloudy (or snowy) and evolving it for an instantly useable Aggron.

As for battling fairy types in gyms, Aggron is slow but quite potion-efficient. Again, not worth stardust from a hatch.

I would go with alot of more options as aggron isnt the best for jynx, I actually do not think its in the top 10. He is def potion efficient but not by a long shot the best potion efficient.

Aggron is quite shit in the grand scheme of things, don't invest dust unless it's 100% (and even then I would still be hesitant)

I caught a lv34 97% and decided to drop 100k into it.

While it tanks hits from pretty much everything it doesnt deal them out at all. I dont regret it but i often roll my eyes at autoselect.

I just evolved a 98% L34 Aron. Got IT/SE on my main account, IT/HS on my 2nd account. Time to compare them.
Disclaimer: It was a random catch, no sgpokemap.

Aggron is definitely NOT worth stardust. Find a high level one.