So I was curious how party exp works and wondered how much exp a leecher will get compared to the attacker. I tried it on low level mobs and the formula of your lvl/(party level) seems accurate. 2 interesting things I found though are that you can't get more than half of the exp of your attacker. For example when I attacked on a level 103 hermit my lvl 180 bishop got half the exp (128 vs 64 exp) and when I added a level 200 bm instead it got 64 exp too. The other thing is that in split leech the formula seems to be seller expXyour lvl/(total party lvl)x1.5 So basically if a seller is 160 and the 2 buyers are 110 and the seller gets 70m exp the buyers will each get 30m exp so you could use it to see how much exp you give to buyers
[Monster EXP * EXP Rate * (1.1 + 0.05 * N)/ (N + 1) ] * (leech level/average party level) * HS bonus where N is party size. If N=2, you get the famous multiplier 0.8, which you can see in a lot of threads generally wrong. (1.1 + 0.05 * 2)/ (2 + 1) ] * (leech level/average party level) = (1.1 + 0.05 * 2)/ (2 + 1) ] * 2*(leech level/TOTAL party level) = 0.8 *(leech level/TOTAL party level) so the multiplier 0.8 is only true for a party of 2 ppl.