When I released the script I asked the beta testers for feedback on what the price should be, most opinions being in the range of $20-25 and $15 per month. I preferred to make it cheaper because while it takes a lot of effort and knowledge to create such a script, it's not going to be a more valuable asset than money making itself, let alone the fact that a woodcutter/fisher/miner is $9. I personally believe a 1 time fee would be better too but that will only happen if OSBot will ever agree with this change.