How Many Sellers Is To Many?

Happy belated Christmas to all thats celebrating!

Im a brand new amazon seller so wanted to get some more experienced sellers opinions on this question.

How many sellers selling the same product is to many.

If a product has 16 sellers but is selling over 1000 times a month, is this viable?

What would you say is a ball park figure of how many sellers to how many times the item is selling a month to determine if you would get involved or not?

Any advice would be great!

Thanks,