Decimal Value comparison with integer value

Question

Hello

I am working on Inventory system

I have a product table which contains Id, item name, SalePrice

the data type for sale price is decimal(18,2)

when I want to add this item to sale list there is a condition that if this item already added to list it will increase the quantity and will not add this item again

the problem is

the product sale price is 50.00 and I add it to sale list if I add again this with 50.00 price product it will increase the quantity

but I change the price to 50 it adds a new item in the sale list

how to change this 50 to decimal then make the comparison in c# windows app