Do I need to file a 1099-K from PayPal if it was for a single transaction that I didn't profit from (essentially reselling an item)?

Yes.  You need to include Form 1099-K information on your tax return as the IRS will receive this information as well.  If you don't report the income, then you will receive a letter from the IRS requiring you to pay tax on the income.  

I'm surprised that you received the form as PayPal states the following requirements for issuing Form 1099-Ks on their website: 

"PayPal will track the payment volume of your account(s) to check whether your payment volume exceeds both of these levels in a calendar year:

• $20,000 USD in gross payment volume from sales of goods or services in a single calendar year
• 200 payments for goods or services in the same year (except in Vermont and Massachusetts where the threshold is lower irrespective of the number of transactions)"

You can also deduct what you paid for the tickets.  The gain or loss from the sale will reflect on your tax return.  To do so, you need to complete a Schedule C to account for the purchase (expense) and the sale (income).  And you are correct, this will essentially be a wash.

See this TurboTax FAQ for steps on completing Schedule C in TurboTax.  Click "See entire answer" for the full page view.  https://ttlc.intuit.com/replies/3302122

Now I am seeing conflicting info from the TaxPros - Massachusetts specifically changed their threshold to $600 versus the IRS's $20,000. Other questions have been answered saying this does not need to be claimed on federal but does on MA. Which is the right answer?

ALL income needs to be reported (claimed) on your federal return and state return (whether you receive a 1099-K or not).  Paypal will not provide the taxpayer a 1099-K unless the above parameters are met.  And the parameters/limits are lower for taxpayers who live in Massachusetts or Vermont.