There is a long thread here on how some cruisers live on $500 per month and another at $5000 per month. I suggest you have a troll through them. Can you live on $300 per month? Undoubtedly yes, because many in third world countries do but they have no choice. In Australia
I think the welfare payment for unemployed is closer to $900 per month so we don't have to. I've met a "cruiser" living on a mooring
just off my local marina in an absoluetly derelict "yacht". I'm presuming he gets at least the welfare amount and doesn't look to be living it up to me. His yacht doesn't even have a mast
so that reduces the lightening risk too. But, do you want to live like that? BTW, he appears to be a lonely old hermit, so it seems that on presumably $900 per month his lifestyle is not that which help him to create many friendships. Just my thoughts. So it seems that most of us would not choose to live on $500 per month and presumably, fewer would choose to live at $300 per month, but yes it would be possible.