$500/month will go a long way in many countries out there or for many life styles. Since we don't know who this person is or how/where they live, I wouldn't automatically assume they need to target a higher MRR.
[1] https://www.numbeo.com/cost-of-living/compare_cities.jsp?cou...
I just wanted to point this out for any potential digital nomads out there - yes it's possible, but probably not in most people's cases, although I'd like to hear stories of people who've made it work. Personally I could never make it work with less than $1k/month - but much of that was due to housing costs.
Keep in mind though the costs of even bare bones laptop & internet connection business models start becoming significant as a percentage when you operate at revenues this low. Replacing one broken laptop is going to eat more than half your monthly revenue, for example - and laptops/desktops are generally even more expensive when you're not in the US or China.