Hi Brian,
Yes, ebay changed listing rules some time ago, they've created separate sub-category for cryptocurrency, but you can only list them as classified ads.
There is a guy who had an ad for bitcoins significantly lower than market value and would sell them to me through paypal. Thought I could buy them and sell them on coinbase. However, I would like to know if there are no safeguards as a buyer in the classifed ad thing
That doesn't make sense, why would anyone sell below market value? Unless he only got small amount of BTC and it's not worth his time to sign up to coinbase/bitstamp etc.
My guess is he's trying to scam you into sending him money as a 'gift payment', so if he doesn't send you BTC, you cannot start a dispute, the only way for you to get your money back afaik would be lying to paypal that your account has been hacked etc
I'd steer clear of it. But if you decide to buy, do it in a small tranches.