first lesson "fee's" is meaningless.

your best bet is to look at https://bitcoinaverage.com/markets#USD
you will notice a price majority difference between $315-$330 (yes there are some at 305-400)

so once you know the range.. you will then see that some merchants tell you its fee free.. but the sale price is higher. then those with fee's may be lower.
so best to get a calculator out and work out the total cost depending on that service, because fee free may not mean cheapest purchase