Hard to know for small coins, Oyster Pearl is good, also consider Deeponion (2018 is year of the privacy coins). You might also wanna consider PnD groups such as
this although its risky so I'd be careful if I were you.
How much will Oyster Pearl rise though, realistically? It's already sitting at around $2.4, and major increases from that point on are rather difficult than buying a coin at like 5 cents and then waiting for it to reach 50 cents.