The first time I made an Ebay search using the keywords "cornhole bags", I was surprised by a few things. I was surprised that there were so many listings; I was surprised by the number of sellers who claimed to sell the "top selling cornhole bags for _________ years"; and I was surprised by the wide range of prices for sets which appeared to be similar.

Here are a few pointers which I believe will help you make an informed decision which will result in your receiving bags which will not disappoint you. There's not a lot worse than spending over $20 to get a set of bags which are worthless...especially when you waited until the last minute and have a party where you plan to use these junk bags! These few pointers should allow you to come away from your Ebay cornhole bag experience with joy rather than frustration.

1. Check a sellers feedback! Unless you're extremely new to Ebay, this isn't news to you. However, keep in mind these things related to a sellers feedback and cornhole bags:
• Just because a seller has a good selling reputation DOES NOT mean that he/she knows how to make cornhole bags. If their previous feedback is related to other items they've sold, they may be a great seller but not necessarily a great cornhole bag manufacturer.
• Watch what buyers have said about their shipping times if you're in a hurry to receive your bags.
• It doesn't take thousands of positive feedback to indicate the quality of a person's work; chances are pretty good that if they've received a few hundred positives without any negatives, their bags will be as good as a person who has a thousand or more positives. So don't overpay for those extra feedback numbers
• Search for the negatives: if a seller has received a negative, look for it! Sometimes you can see that they didn't deserve it (for instance, I saw a negative left for a cornhole bag seller which said something like this "there was a seam on the outside of the bag, you didn't say there would be a visible seam". Really? A negative or two like that shouldn't scare you away! 
2. Add together the selling price and shipping to get your TOTAL COST. Don't be fooled by the seller who sells for a low cost, but jacks up the shipping a large amount. In the same way, don't be sucked in by the seller who says, "We charge only actual shipping, unlike other sellers" while jacking up their actual purchase price. If a seller charges $15/set and $8.95 shipping (total of $23.95), they're not treating you better than the seller who charges $9.99 and $10.99 shipping (total of $20.98).
3. Don't pay a lot extra for a Lifetime Guarantee! Read the fine print of these sellers. It's not a bad idea, and chances are pretty good that they'll honor that guarantee as long as they are still making bags when yours breaks. However, almost all sellers who offer this guarantee will require you to pay the postage to send the bag or bags back for replacement. What this means is that you are shelling out more money (depending upon how many bags you're shipping back, it will be between $4-$9). Don't run from the lifetime guarantee, but also don't pay a lot extra just to get it (it won't be worth it in the long run).
4. Take note of the outside stitching. If a picture shows that the topstitch thread doesn't match the bag color closely, then that seller isn't an expert. Those who have been in this business for a while know that nylon upholstery thread can be purchased to closely match every color of bag. You're probably buying from a Wal-Marter if you see bags like that.
5. Focus on the essentials! Sellers are really good at "fluffing" their descriptions. Look mainly for these essentials, and use the "fluff" as extra reading if you'd like:
• Do they make regulation bags?
• What thread do they use?
• Do they use duck cloth/canvas? (Please note: there are a few sellers who like to say that they use Duck Canvas rather than Duck Cloth...thus they jack their price for this special material. They are one and the same; some manufacturers call it Duck Cloth while some call it Duck Canvas. Don't be sucked in!)
• Are they filling with whole shelled corn? (It would be a good idea to make sure they're using dried corn as well...if they're just getting it from a farmer and not a local feed/grain mill, it probably isn't dried. Thus, the corn will dry in your bag and you will experience a significant weight loss).
• What kind of a discount is offered if you buy more than one set?
• What does their feedback say about shipping time? If you're in a hurry, focus on this one; if not, then it's not an issue.

Hopefully this guide will keep you from purchasing bags which will cause you a lot of disappointment. There are a lot of good cornhole bag sellers on Ebay; there are also a lot of sellers just looking to make money. If the seller meets the above criteria, you should be pleased with your purchase.