Even $100,000 would kill it. If 1 sat (or even 100 sat) == $1 then the fees would grind the system to a halt. The fees would be so high relative to the amount sent, that it wouldn't be worth it. From an investment perspective 1 sat==1$ is a nice round number. From a users perspective, only being able to buy things divisible by 1$ is crap.
Don't stress out yourself yet we wont even reach up those numbers.Okay lets presume that we are already into these levels.
Fees wont really be a big thing as long the network isn't congested.No matter what would be the price if the network isn't busy then fees would
really be just still on minimal state.