Category with $1 product,and limite purchase quantity

I have a shopping store and have a category with $1 product,when shopper buy more than $100 in my shopping store ,he can purchase 1 product in $1 product category,For example:

1. Buy more than $100 in my shopping store , limite purchase 1 product in $1 product category;
2. Buy more than $200 in my shopping store , limite purchase 2 products in $1 product category;
3. Buy more than $300 in my shopping store , limite purchase 3 products in $1 product category;
4. Buy more than $400 in my shopping store , limite purchase 4 products in $1 product category;
5. Buy more than $500 in my shopping store , limite purchase 5 products in $1 product category;
   ......

how to do?

anyone help me.