Here is the escrow thread...the cost is $20 + shipping. If you are buying an item from a new member you are taking the risk associated with it. If you escrow you pay Marcus (or even split if both parties agree etc) $20 + the shipping to him, and then to the new owner assuming the transaction is a go. This way the original seller can't scam you and take the payment and not ship the cue. You will send the payment, confirm the receipt of the payment to Marcus, and then Marcus will ship you the cue.
http://forums.azbilliards.com/showthread.php?t=115543
In terms of paypal if you sent as a gift you are SOL....if you sent as a regular payment you have a certain time frame to open a dispute to get refunded. Depending on how much the $ is I would assume will determine how involved they get with it. An example is they may not overly care to look into it too much and just refund you for a $100 on an item you did not receive, but for $3k, they may investigate the transaction a lot closer. I am not an expert at this keep in mind so it's just my opinion on what I have read/heard in the past.