I don't think you are going to be able to find anyone who is willing to sell a Hero+ account for .3 BTC. Generally speaking senior accounts can easily fetch that much. IMO you probably will need to at least double your budget, however even that may not be enough if you want a higher level hero and/or want good quality posts.
Let's see.
0.3 BTC is more then 70 bucks after all, and I doubt they are worth more than that.
In the past Hero accounts have sold for 2-3
BTC, and sometimes more, however prices have fallen a lot as Hero accounts have become less rare.