Retirement tax questions

Hello and thank you for your reply!  So, in this particular case, I sold record albums from my personal collection.  Some I've owned for 15+ years, some for much less...  Needless to say, I definitely don't know how much I originally paid for them.  Further, it would be an incredibly daunting task to list each album I sold over the past year -as there were many.  

 

All of this said, do you have any recommendations for me?  Can I just remove my 1099-K form from my filing?  I'm in TN which doesn't have an income tax anyway...  It's just extremely unrealistic to think that I can itemize all of the small dollar sales that I had over the past year, let alone compute how much gain/loss I incurred from each sale.  

 

Any help you may have would be greatly appreciated.  Thank you!