Buy a little bit of bitcoin every week don't care if it's a $1, $5, $10, $100, figure out what you can afford every week and buy it, get rid of unnecessary expenses or whatever you can think of getting rid of and spend it on bitcoin
5 to 10 years if you buy some every week you will be a multi millionaire
That's a famous Dollar Cost Averaging strategy.
This strategy does not seem effective to me, because the investor averages too much, investing small amounts of money over a long period of time. I understand that in this case you cannot buy bitcoins at the maximum (this is good), but you also cannot get the best position for investment - I mean the price of bitcoin at the minimum of its price range. Isn't it better to hold fiat and wait until the price of bitcoin is at its minimum? For example, build a ladder of orders, and in each order try to purchase bitcoins cheaper and cheaper.