Are you keeping an inventory because it's really a cost of goods sold thing.....you can make this an expense in the Misc category if not.

Just report the income in the business income section, and report what you paid for the inventory you actually sold in 2019, in the Inventory/Cost of Goods Sold (COGS) section. The program takes care of it.

Example:

Lets say you have 100 widgets that you paid $1 each for, and you sold them for $0.50 each. The business income will show $50

Meanwhile in COGS you will show that you paid $100 for that inventory you actually sold. The program will work it and "know" that you have a $50 loss. Not a big deal.