Please help this is the only question out of 6 i cannot solve..

Phillip, the owner of a vineyard, estimates the first 9800 bottles of wine produced this season will fetch a profit of $5 per bottle.

Howeer, the profit from each bottle beyond 9800 drops by $0.0003 for additional bottle sold.

Assuming at least 9800 bottle of wine are produced and sold, what is the maximum profit?

What would be the profit per bottle in this case?