My recommendation is to start with no less than $500-$1000.
You need to buy traffic to learn.
If you’re losing money at first like most people do, then you’ll get better and better and better and closer and closer and closer to breaking even. And eventually, you’ll have that first product that just takes off and you don’t want to get run out of money before you get to that stage.
Because the worst thing that could happen is that you’ve invested money to be better at paid traffic, you’re starting to get a few to your niche and just when you’re getting close to that point where you could become profitable with, that is when you’ll run out of money and you’re forced to stop.
That is a huge pain and you want to avoid that at all cost. I always tell students they need $500-$1000 budget, I think that sets you up to have enough.
To be honest, it only cost me about $250 of the testing budget to become profitable.