How much money should I spend per day on an Adset for a new product?

I'm relatively young so I don't have that much capital to spend on FB ads.

I was watching one of Paul Lee's videos and he said to gauge whether a product is a winner he initially spends $50 per day across 10 different interest groups. To me this seemed a bit much since this is my first website I set up and bought a domain for.

All tips are welcome!