Not exactly sure what you mean by "writing off" the $40 in shipping. To follow-up on the comments from @JamesG1, if the shipping costs for the vacuum were $40, then you include that amount in the cost basis for the vacuum. By adding it to your cost basis in the vacuum, it does not necessarily get written off per se, but it does get accounted for when calculating whether you had a gain from the sale.
Yes, reporting the 1099-K as other income, with corresponding negative entries, is the correct approach.
@c_man99
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
