Carl Sagen was talking about billions and billions of stars, but he could have been talking about used golf balls on ebay. There are a lot of them, it's a buyers market. I see prices on ebay way lower than most flea markets and resale sports shops, not to mention the delivered to your door convienience.

                    The best advise for golf balls or any  item is to read the sellers feedback BEFORE you place a bid. Many buyers don't look untill after there is a problem.  If the seller has several negative feedbacks, look out. Lots of mutual retractions are also a red flag. Read the tone of comments from buyers, you can learn a lot.

                How much are used golf balls worth?  Just like used cars, their cost when new and current condition are the factors. A nice Caddilac or and old Chevy? So if you know the price of new balls you can figure value based on the condition.

                     The Titleist Pro V 1 and V1x are the MOST sought after and MOST fragile ball in golf. If you insist on them, be aware they scuff easily, turn off white quickly with age and abosorb water when exposed to the elements. Many companies repaint and restamp  them, usually remembering to print the "recycled" disclaimer on them. Most used balls can still look brand new, but most $40+ a dozen balls just don't look new for very long.

                  The A's rating system is most common on ebay.  An A grade being the worst, AA being OK, AAA almost new and anything with  AAAA or more? should be like new in condition and  worth about one half their cost new. You can deduct accordingly as you go down the A scale. It's pretty subjective, so once again look to their feedback history to judge for accurate descriptions and pictures. 

              Some balls are not even worth the shipping fees. ebay has cracked down on excessive S&H fees, something  that happens a lot with used golf balls. toddpelotas charges $12 S&H for 100 balls to any US destination. This includes insurance and delivery confirmation. Don't pay more than $12 per 100 balls for domestic S&H. Delivery should be confirmed and the buyer satisfied with the product before the sellers obligations are completed. Just like the movie Miracle on 42nd St.

                    Good luck bidding. There are some great deals for golf balls on ebay.  Remember, you are going to loose them soon enough, so don't pay too much!