We shop for a ton of Sports Cards (Mostly Football) in order to get boxes to rip on our channel. Below I will list the places i normally shop and have had good experiences. Not listed in any particular order as each can have deals on a certain box on any given day. We recommend searching all below websites for the best price on the box your looking for.
1) https://www.blowoutcards.com/ Blowout is one of the biggest (if not the biggest) Sports Card retailers online. In our experience, they are generally more expensive than other sites but provide rock solid service. They also have the largest selection of sports cards we have found and are usually the first to reflect the latest updates to product release dates.
2) https://www.dacardworld.com/ Dave and Adams also have a very large selection of boxes. Like Blowout they have a lot of overhead so they will generally be near the same price as blowout. They also provide rock solid service with fast shipping and are quick to respond to any customer issues.
3) http://simsburycc.com/ Cards and Comics is another great place to shop for older boxes of cards. You can find good deals on their website if you search for them. We have used them many times and were always satisfied with the purchase experience.
4) https://www.diamondcardsonline.com/ Another site that offers preorders and a small selection of hobby boxes. We have used them a couple times and service was ok.
5) https://onlyatgrandslam.com/ One of Ed's favorites.. If you stop in here during the right times you can find some of the best deals on the internet for the newest hobby boxes. excellent customer service as well.
6) https://www.meelypops.com/ Another site where you can sometimes find a good deal. Decent selection as well but often sold out of the most popular stuff.
7) https://hitkings.com/ Football preorders and a medium selection of hobby boxes in all sports.
8) https://collectorstore.com/ Another great site we use often. they carry all kinds of cards including TCG and sports including some retail boxes (at flipper prices) as well as supplies. We have always had a positive experience here as well.
9) https://www.charmcitycards.com/ Another large site. We have not used them yet as they are generally higher priced than other sites above, but there is always potential to catch a deal.
10) https://laytonsportscards.com/ One of the biggest breakers in the hobby, Layton also offers individual boxes for sale either ripped or shipped sealed. you can catch deals here too on sealed boxes every once in a while. We have done breaks and purchased boxes from them and they are one of the best in the business at customer service and card handling in our opinion..