How do you buy an IPv6 address?
You're not even supposed to buy an IPv4 address, but a market for IPv4 addresses sprung up due to their scarcity.
Now, I'm not trying to be pedantic here. To obtain an IPv6 address, you need to be allocated one. And that's the job of your ISP, apparently. Which kind of makes sense since 1) that's how your home computer gets an IPv4 address (a dynamic one, these days), and 2) unless your ISP supports IPv6 you'll need to set up some sort of IPv6-over-IPv4 tunnel anyway.
Now, you may say "oh dear god are there any options that don't involve my ISP", and, well, good luck: https://www.apnic.net/get-ip/get-ip-addresses-asn/
By default when you're allocated an IPv6 address you get at least a /96 block and thus you'll never run out of sub-addresses, so you really only need one.
I just didn't have the willpower (or wallet) to see it through. I was merely doing it for fun and burning a bunch of money for addresses that I would barely use didn't sound fun after thinking about it. Still, it was fun chatting with my friends on IRC about it and it is a very interesting icebreaker!
Alternatively you can become a RIPE member and request all of the resources yourself, but that’ll cost you €2550 on the 1st year and then €1550 yearly.
You don’t need to be physically located in RIPE region to go the RIPE path. All you need is _connectivity_ in the region. A $5 BGP VPS counts as _connectivity_.
> or be a multi-homed site (would have required getting a second ISP to my residence, I believe?)
No. You needed to get 2 BGP servers. Another ISP to your home would be useless unless they both offered BGP sessions.
Of course the $35 doesn't include the VPS you'd need for actually announcing, but this is a _very_ cheap way to get into BGP.
Where did you get the /96 from? A /96 is basically useless.