$10 constant investment will amount to little in the long run and almost a messy way to start up a bitcoin investment, I think also that for anyone to arrive at a successful investment position one needs to be aggressive a bit, at least that will help us to be able to take some aggressive financial decisions that can help us to arrive at a good investment position faster.
Investing a low amount like $10 as mentioned by members sounds like a joke considering Bitcoin's current value.
Although investing $10 in bitcoin may seem small, and it will take a longer time to reach a good amount of bitcoin for that reason, don't discourage anyone who has made a move in accumulating bitcoin, even if the money the person is using to accumulate bitcoin is small, as that could be the available money the person can afford to invest in bitcoin. Achieving successful investment has nothing to do with how much money you have invested in bitcoin, but when you have successfully come to the end of your accumulation journey and you reach your desired outcome, you have become successful in your investment.
Irrespective of the invested amout the most important thing is that you are comfortable with your investment without suffocate other important needs. So if your income flow restrains you to invest only $10 using DCA probably per week than that's fine. Just like len01 said, if you have the mindset of increasing your bitcoin investment, you can try looking for another source of income that gives you a more opportunity to increase your accumulation amount while other needs are also being taken care of. The most important thing in bitcoin investment is that you feel comfortable with your investment and also have a reserved fund to take care of emergency needs or situation that need immediate financial intervention. That is, a salary of $2000 and after making a monthly expenses of $1500 you can make a $100-$200 investment in bitcoin while the remaining amout is kept as your reserved fund depending on how aggressive you wish to go with your investment. With the rate of $300 as your reserved fund in your fiat currency, within a space of 5 months you should have accumulated one of your total monthly expenses $1500, but the goal is to have a reserved fund worth 3-5 monthly expenses. Then you can become more aggressive in your bitcoin accumulation because what's the point accumulating so much in your fiat currency when it only loses value, if not for the sake of emergency needs?