First, do not buy XRP. Ripple is not XRP. Ripple is a private company who most likely released XRP as a play toy for speculators which will never be used by their company and their partners.

Second, don't look at per coin price. Market cap is much more important. Some projects, like bitcoin, have 21mil tokens, and projects like ripple have 38 billion tokens. See the difference ?

Third, you'd have to study them, to see what their potential is. Keep in mind that projects that aim to become currency don't have any chance of real succes. See bitcoin, after 8 years it's value depends on speculation, and most places that used to accept it, doesn't anymore, because of the low volume and the fact that people hold it for speculation purposes.

I suggest you to check ethereum, currently it is the only project that can become really big. One example ( there are many ), United Nations ended a pilot program and they want to expand it further, while using the public blockchain as implied by the second link

https://insight.wfp.org/what-is-blockchain-and-how-is-it-connected-to-fighting-hunger-7f1b42da9fe
https://www.reddit.com/r/ethtrader/comments/6144xe/ill_just_leave_this_here/dffpbf1/