$20 per client. You can use for 1 Window per month, gotta get a new key next month. So what is it, if I want to use another client I gotta buy another key?
L2Net used to have lifetime keys, min $ for donation.
Here are more limitation:
License A and C (1 window) allow you to use bot in 1 Lineage client, so to bot on more boxes you need more license keys.
To play on EU Classic server (4game) you can ONLY use license C.
To play on RUS or private Classic server you can ONLY use license A.
To play on private servers with Smart-guard antibot - you can ONLY use license B (limited one won't work).
License keys works for 31 days, counted from first use in bot and needs to be bought again to continue of use.
License keys has no expire date - you can buy and store them for future use.
Adrenalin doesn't bypass box limit of your server, so keep that in mind when selecting license and amount.
There is no trial (disabled after abuses) or lifetime licenses.
You can move your license to other PCs freely, any time you want - but it can be used only on 1 PC at same time.