Bitcoin does not treat rich or poor differently. no minimum or maximum investment is mandatory for anyone. You can invest just a few cents in Bitcoin. It totally depends on your ability. You will profit according to the number of dollars you are able to invest and lose if the price of Bitcoin falls. and the more you invest, the more you gain, on the other hand, the more risk you have to take. Bitcoin gives everyone the highest priority in their freedom. so here you can always give more privacy to your own desire. so invest as much Bitcoin as you can afford. But your ability should be long term.