How to calculate Open-to-buy:
Open-to-buy = planned purchases - (orders received + merchandise ordered)
Planned purchases = $2,500
Received orders = $1,200
Ordered merchandise = $700
Open-to-buy = $2,500 - ($1,200 + $700)
Open-to-buy = $2,500 - $1,900
Open-to-buy = $600