hi,
is the type of the item a column in the cart?
if so, i think you can just do a discount like:
- number of items with a specific column value
if the total number of items where "product type column"
has a value of "type 1" (whatever type 1 from your description)
and you want it to be > 9.
then at the bottom, the calculation would be
"based on items with a specific value"
total of "product type column" where the "product type column" has a value of "type 1" times (the discount amount per item).
describing better:
if i have product-type column, and the type=shirts, price is 10 with a discount of $2 per shirt if they buy 10, this would read as:
number of items with a specific column value
if the total number of items where "product-type"
has a value of "shirts" is > 9
at the bottom
"based on items with a specific value"
total of "product-type" where the "product-type" has a value of "shirts" times 2.
hope that this works for you.