Coinbase fees are strange

If I put an order to buy: $100 fee is $1 $200 fee is $1 $201 fee is $2 $300 fee is $2 $400 fee is $3 $500 fee is $4 $600 fee is $5 $1000 fee is $9 So it's always cheaper to put multiple $200 orders through than any other amount? Their fee structure seems screwed.