You find a item you want to purchase but it is listed with a reserve. Does the seller hope to create excitement and bid activity with a low opening bid.....or is the item so far overpriced it is a total waste of your time to even follow the auction? An item starting at $100 may have a fair market value of $1,000. It may have a reserve of $500 or a reserve of $5,000. Why waste your time participating in auctions that the seller has expectations that are unreasonable or greatly exceed your ability/desire to pay?
Discovering reserve may be done by either a direct or "back door" approch. The direct approch is to simply use the "ask the seller" feature of the listing to ask the seller his policy on disclosing reserve. Disclosure of reserve is something many sellers have no issue. Some sellers treat reserve as some type of national security secret. Either way, it does not hurt to ask.
Often the reason a seller will not disclose reserve is he realizes the reserve is above fair market value and he is "fishing" for "the one guy" who does not care how much he overpays. That is a legitimate approch, but it you are not "the guy" such sales can be a waste of your time.
If a seller ignores your request of disclosure it may be possible to get an idea of the sellers expectations by going through the completed sales features of eBay to see if the item has been listed previously. Use the key words of the listing title to show current listings. Go to the yellow options box to the left of the ad and check completed sales. Often the item will show as a completed sale. This feature displays items for only a week or so. If the item does not display try the site map feature at the top of the page. An Ebay main menu will allow a search by seller. This feature will allow a review of the sellers completed sales for up to 30 days.
read the full guide with pics here