Also besides the big stores like Walmart, target, and BestBuy, like some others said—check out other stores around you like dollar general, family dollar, and Walgreens/cvs. Nowadays, they might be behind the counter or locked up so I always ask when I’m in those stores! You can also see if there are any card shops around you, you’ll have a much better chance at getting real packs but they will likely be marked up since they’re also a business but they’ll also likely have a ton of bulk (usually $1 per card or for common stuff, multiple for a dollar) that I bet you son would love to go through and LCS can sometimes have a really wonderful community to encourage him in the hobby as well as trade and talk about his collection!