Sale of Sports Cards and expenses

Hello. My husband bought and sold sports cards online last year.  The 1099K says there were 75 transactions in total. The amount in "income" was a little over $19k.

His expenses for purchasing the cards, supplies, etc. most likely exceeded the income, however, we have only been able to pull together about $17,500 worth of expenses - there are 109 separate transactions for expenses. 

I am uncertain how to enter all of this information and if I have to enter each separate item.  I could possibly allocate each box purchased to the sale of cards, however, how would I tie in the supplies? 

Thanks!