The bounty page blurb says this:

"Bounties each cost a minimum of £100,000 per level of the target '

I just placed a bounty and it cost me a lot less. I don't know how to see a list of bounties but it was more like £1k per level?

Thanks for pointing that out, originally they cost a minimum of £100,000 per level but that was prohibitively expensive. I've fixed the text and will deploy it live shortly.