Is this a scam?

I would appreciate some help with this, which has happened to me in the last few days.  I listed an item on a site, not Audiogon but another one, and got an offer within a few days.  The offer was lower than asking price, but reasonable, so I accepted.  All of this happened with an exchange of emails.  The buyer wanted to send me a deposit which was about 1/4th of the total sales price, and that amounted to a few thousand dollars.  He said he would send the rest when the item was shipped.  I thought this was a little strange, but agreed to it -- today I received his deposit via Paypal Friends and Family.  Somehow I wish now that the money transfer hadn't happened.  But the good news is, I have not yet sent him the items.

The guy has very little purchase history on the site that was used to contact me.

He says he has a Freight Forwarder and and will have someone pick up the items.  All of this seems suspicious to me.  I fear that perhaps I have been paid with a stolen credit card number, for example.  Of maybe there is another angle here that I cannot perceive.  Has anyone else been through a process like this?  I think he is a scammer but don't know for sure.