My guess is, that Meta will try to control the public image of the name Mastodon. Yeah the Software itself is OpenSource and protected under AGPL-3, but they still can buy Mastodon GmbH and use that to tie their name to Mastodon for the broad public.

Have a look at an nvme ssd and an enclosure for it. I’m using a icy box one for mine. This way you can get 2tb storage for about 130€. There are a ton of options regarding enclosures. If your budget allows you should get two for additional backup security.