Discount policy for regular online store buyers

Discount policy for regular online store buyers :
The product with unit price < $200 is global discount enabled, our online store  offer 2%/3%/4%/5%/6%/7%/8%/9%/%10 discount if total global discount enabled products is $500/$750/$1000/$1250/$1500/$1750/$$2000/$2500/$3000 (Exception: Products with wholesale price or with unit price >$200 are not qualified for this discount)