The reason that you are getting so many instructions is that you have several options for how you enter something like this. The easiest is to enter the net gain as regular income and call it a day. Personal item sales are only taxable if they have a gain and then only the gain is taxable. You properly separated them out and so you can easily enter in the amount that is not subject to income tax. There is a box at the top of 1040 schedule 1 just for that purpose now.
When you enter the 1099-K into TurboTax you will enter all of the information from the form and then check the box for 'Personal Item Sales'. Then, on the next screen, you will check the box that says "I sold some items at a loss or had no gain." In that box you will enter the amount that is excluded from income (in your case $3,237.11) and then it will enter everything into the forms just fine. Save your records in case there are ever questions and you're done.
**Say "Thanks" by clicking the thumb icon in a post
**Mark the post that answers your question by clicking on "Mark as Best Answer"
