I looked on the website. This is actually an “early bird” special price that is ~80% discounted. So after a while, it’s going to be $162/year and $310/2 years.
I don't really pay attention to these "discounts". It is, generally, just a marketing tactic. Plenty of services/websites/shops have the same discount 24/7.
Can I do something like this on a Raspberry Pi?
Something like Syncthing, but for hosting media would be fantastic. No need to deal with opening ports in the router and all those shenanigans. Something that you install and it just works, without any additional software. Is there anything like this?