Any amount is suitable for a new investor to start investing. Even a small investment of as little as $10 can kickstart their investment using DCA. The problem is that some cannot keep up with that $10, after some time they get to stop investing in Bitcoin. But come think of it, $10 is quite a comfortable amount for anyone to be able to DCA with. Any investor who can't keep up with a minimum of $10 investment every week should not be investing in Bitcoin.
This might be misleading and can scared some newbies from starting their investment, you have to speak for yourself in terms of amount you can be comfortable with, perhaps Bitcoin investment shouldn't be seen as a burden, the dca gives enough flexibilities in terms your allocation amount on different intervals, if a newbie kick start investment with $10 either weekly or monthly, it is not compulsory that he must meet up with the $10 all the time, I believe there are times when our expenses become more than previous weeks or monthly, we can increase or decrease our DCA amount based on the available discretionary income, what we should mostly prioritize is investing within our individual financial circumstances to enable us have the peace of mind needed to grow out asset even though am not insinuating that we should be wimpy with our investment.