wise decision but I think $10-$20 wouldn't suffice for good profit even in altcoin that fluctuates a lot personally I think if its below $100 then its better to keep saving until it reached $100 but that might just be me.
personally I would do the same, putting majority of investment into bitcoin and ethereum and the rest for rather volatile investment that i could still afford to lose because we all know that 90% of altcoin are gonna fail anyway.
but in the recent events i've seen many coins that has partnership with the like of coinbase as for example always gaining success that it make me think whether its worth it to allocate more and more money to these alts since future are promising and the investment company behind it are ensuring smooth listing in various exchange that it'd be great if i could make some profit that surpass 100% just by holding half a year.
current bullish truly shows the potential of these coins tbh.