In order for you to claim anything as a tax deduction you have to be able to demonstrate that the item is in substantial use in order to derive your income. With only two sales that will be very difficult to justify.

If you go ahead and claim it anyway and you get a desk audit you will have to offer the proof to the auditor. If they are not happy then you will have to repay the amount you claimed plus pay a fine for false declaration.

Basically for them to believe you then you will need to be also declaring all the income (from ALL both sales) you have derived from your business venture. Bit difficult I suspect.

You need to talk to a tax accountant. They will set you straight.