Dang I'm so jealous, not from the money they make but I just want a freaking +15 weapon already.
Anyway, if anyone needs some more explanation on why this is done via enhancement runes, here's a post I made yesterday summarizing my observations:
1. There was a video a while back showing +10 to +11 with rune in Mabinogi Heroes. This may or may not be related.
2. All the sellers of +15 weapons require an initial deposit of $50. This is presumably to buy (at least some of) the runes that will be used for the enhance.
3. The cost of the +15 weapon decreases if the original weapon is already at a high enhance level. Probably due to needing less runes in these cases.
4. The hackers refuse to give Nico a random low-level +15 item to prove that this is real and boost credibility and sales. This is because it will cost them money to enhance this random +15 item.
5. The process does take some time to do, and as one seller mentioned, "involves risk." A true enhancement hack would just be to enhance every time and it succeeds. This is not really a true enhancement hack as that would be too good to be true. Enhancing with runes will take some time, and the amount of runes needed varies, it could potentially cost the seller more than $500 if he is really unlucky.
Btw, if this is really done via a console command, don't bother searching the public lists. Whoever dumped them probably knew about the command and removed it before he posted it.