I got a coin that I haven't put up on to exchanges yet, but probably will in 2020 or 2021 - It'll be timed to go up about the time BTC hits $20k. I can mine it with a regular comp and get like half the blocks lol... so pretty sure it's possible with Raspberry.
Once it's on exchange, difficulty will go WAY up... so not bad idea to get a stockpile now... and the reward is super finite (I did this for a reason)... so 1 coin could be like $400 in a short time (if it gets popular), but today you can mine 3 coins per day pretty easy.
Total output per day is 30 coins roughly... which goes to 15 coins in late 2020. Other than that, same rules as Bitcoin.