You can wait a little time with a lower price value, so you can get better profit with you buying bitcoin. because the future of bitcoin is very good in the future.
it has been mentioned that OP has a capital of $30, I think it would be nice if to buy ethereum, because ethereum is cheaper when compared to bitcoin, and ethereum is also a potential coin
ethereum now has a stable price and the risk of loss is very low, so there is no harm if choosing ethereum as one purchase rather than choosing a new coin but can not be used as a potential benchmark coin.