Can you actually buy it though? I have it in the back of my mind that they restrict sales of ida pro and the decompiler as an anti piracy measure.

What do they think the people who want this are going to do if they can't buy it legally? I can't imagine it didn't cross their mind that those folks are likely to just...pirate it. Awesome "anti-piracy" measure.

There's some level of restriction, but copies still leak fairly often. Usually you're a few versions behind running pirated copies, rarely more than that.

Many people are however used to working with its output, not due to having purchased copies, but due to having pirated copies.

They certainly don't have a process where you can just "add to cart" on their website and hand them a couple thousand dollars. I'm not sure what extra checks they do through their sales team; maybe they're just trying to make sure that large businesses aren't buying up single-dev "Named" licenses and installing it across their organization, or maybe they're trying to verify that buyers are known security researchers, or something.

Umm, I bought my license by doing exactly that — add to cart and fork over a few thousand dollars. I don't remember them doing any verification other than requiring a business email address.

Pirated IDA+hex-rays is the industry standard.

My employer has a copy. I'm confident they acquired it legally.