We should not underestimate the power of little, we can start small and grow big with time, there are few ways i can suggest for us in doing this as i think it's not something new, we might have been used to them in may occasions, we can go on trading with that money and allow it to continue growing in it, we can also recommend holding it after we would have acquired bitcoin by buying the dip with $30 and holding for the next target of bullrun after halving, we must also be reminded that everything about this decision takes time and patience.
What other investments or assets can you invest this kind of tiny amount and expect huge returns? People are being ridiculous with BTC, it is simply decentralized money that is volatile and can rise because of fixed supply and demand, it doesn't provide magic revenue. If what you can afford is $30 for dca, then it is fine, but don't expect huge revenue or to save up 1BTC which is almost impossible or will take forever as price will continue to rise. Don't even talk about trading with only $30 to get up to 1BTC!