One of the largest and most reliable places to purchase cases of baseball cards is through online sports card vendors and distributors. Buying in bulk directly from these sources allows you to get good deals on full sealed cases. Some top options for case quantities include:
Dave and Adam’s Card World: They are one of the largest and most well-established online sports card retailers. DACW sells sealed cases of most recent MLB sets from Topps, Panini, Leaf, etc. Cases typically include 30-36 factory sealed boxes. They guarantee the cases are shipped sealed to preserve the randomness of packs. DACW also sells cases of older vintage sets from the 1980s-2000s when available.
Steel City Collectibles: Another very large online card vendor that maintains stock of sealed cases. SCC has MLB licensing so they can sell sealed wax cases of current Topps flagship and Allen & Ginter sets. They also get inventory of sealed cases for Panini sports releases. SCC aims to keep prices competitive compared to other distributors.
Blowout Cards: Known best for individual singles but also sells sealed boxes and cases from manufacturers. Blowout gets inventory directly from the sources so you can buy sealed, randomized cases with confidence in their quality. They stock cases for MLB, NFL, basketball, soccer, and non-sports releases currently being produced.
Dave’s Cards: More of a specialty hobby shop located in Florida but also does online case sales. Dave’s works directly with card manufacturers to get sealed cases prior to public release dates. This can be a good option if you want to buy a case of the newest hot set before elsewhere sells out. They charge a premium for the early access though.
Lelands: While more focused on high-end vintage cards and auctions, they do periodically list sealed wax cases from the 1980s-90s on their website. These old cases contain 36 factory sealed packs or boxes and are a nostalgic way to try ripping vintage wax. Lelands tests the seals are intact before shipping the full unsearched case.
Beyond just online retailers, you may also be able to find case quantities from local hobby shops, collector shows, or group breaks run through Facebook groups. Some hobby shops will break larger wholesale boxes into pre-organized subsets or cases that they then resell. Collector card shows sometimes have vendors with sealed cases for sale too. On Facebook, groups dedicated to group breaks or case breaks may periodically have extra full unbroken cases available for sale at a discount after a break event. Buying directly at local hobby shops or shows removes shipping costs but may have less selection versus the major online distributors.
Wherever you buy from, look for guarantees the cases are sealed by the manufacturer and have not been searched or tampered with prior to arriving sealed in your hands. Reputable vendors know intact sealed cases are important to maintain the integrity and collectibility of the cards inside. Request seals be intact upon delivery too. Cases purchased directly from major distributors like Dave & Adam’s or Steel City are safest bets for genuine factory sealed product.
Another option is to watch eBay for auction listings of sealed cases, but there is more risk the seals could have been broken without the seller being truthful about the case contents having been searched or resealed. Seals can also get damaged in shipping if not properly packaged. So cases from known hobby retailers tend to be the most reliable sources versus taking that chance on an individual eBay case sale from an unknown seller.
With cases, you have the fun of doing a large group break of packs/boxes with family/friends or turning around and doing individual randomized box or pack breaks online yourself to gain subs. There are also speculation opportunities to store sealed cases away long term for potential future appreciation as investment holdings depending on the particular sets involved. Buying in case quantities through reputable dealers allows you to maximize value for money while preserving the integral randomness and collectibility of the cards inside. Let me know if any other questions!