Why would they need to buy it when they can just install iMacros in their browser and record their own actions ?
Also as what paradoxal420 mentioned, lag and overbets could ruin it. There are already too many bots here
A bot is desirable by many people, if they want to run some kind of strategy thaat requires many bets. But bots like these, are for people in cases when the current PD bot can't be set up to perform in the required manner.
Just a word of caution, do get the bot reviewed before using it. If you don't have 2Fa enabled, these scripts can possibly withdraw all your balance to an address that belongs to the coder.