It does suck, I'm hit by the same deal, and got the email last week when I was in the middle of calculating my taxes. <insert profanity here>
While I'm not an accountant, or tax professional, what I've been able to gather is that even if you are not a business, you have to report all income. They're looking at profit. By law you are responsible to report any sale in which you made a profit.
So there's several things here.
Part of your sale includes shipping. You'll need to have all your ACTUAL shipping costs for this. (If you charged $5 for shipping, received $5 for shipping in PayPal, but paid $6 for shipping, the $6 is the deduction)
You use PayPal and ebay fees as deductions.
Actual sale of the item - (original cost of item + shipping + fees) = profit. It's the profit that factors into your income. (The actual sale of the item is the item selling price + shipping charged)
Unfortunately you have to remember the cost of what you paid for the item. And the loose parts I sold from my collection? Oh dear God I'm gonna start drinking now!
Form C is to report gain or loss from a business, but I believe there's one for personal.
Calling yourself a business now to try and save some funds or get tax breaks won't work for 2011 taxes as you would have needed to been a business last year. PLUS, you'll now have to show invoices for the purchases, and if you sold to anyone in the state you live, you are guilty of failing to pay state sales tax. You'll also need to pay for licenses (CT has an LLC fee of $250 every year). I have an official business for the shows I do and just like the folks that are online resellers, there's a lot to it.
Again, I have the same issue as I'm selling off over 20 years of my collection. Figures, loose parts, Legos, etc. Who'd a thunk I'd ever sell that much on ebay? More so, where's the cash?
I can't blame PayPal for this. It's our elected officials and various federal agencies that wanted a bigger slice of the 99%'s pie. What pisses me off about ebay is they no longer allow money order or check, and given that the feds never investigated them for it, helps me put 2 + 2 together.
John