RPG

I don't do Sci-fi, but as a former Syrinscape subscriber, my solution has been to buy a soundboard app I like, and then download very affordable tracks from independent artists via Bandcamp. There are lots of artists who charge $1 or 2 for a 1hr album of tracks, or even "pay what you want." Even better, if you find an artist you like, you can sometimes get their whole discography for like $15-20. Obviously, you can also rip mp3s or whatever else.