vod.org is available. It's only $40,250.
I think that if you can get a domain name for under $10 per year it's worth it. It helps to build your internet persona, and you can use it to boost your signature revenue if you are prepared to work it.
Yes, you can sell it with your account, but then you are selling a business, not just a board ID.
Registering your Bitcoin address here is an essential imho, but it is additional security.
It can be hard to find .com domain names these days. I find the name first, and then use it as a board persona.