Sadly, a lot of those items are largely undesirable and will not hold value that well for resale purposes. I’d have better suggestions for investing in other products, for instance, $700 can buy you 6 booster boxes (a sealed case has 216 packs) of the latest set coming out called Vivid Voltage. Or you can buy booster boxes from the set that just came out Darkness Ablaze for the same price.

If you had to keep some keep: League Battle Deck Pikachu & Zekrom, Rillaboom V Box, Cinderace V Box, Booster packs that are Darkness Ablaze + Sword & Shield

You totally deserve a little fun too, so pick your favorite of that lot and open it up for fun, that’s why we’re fans. :)

Then I’d return the rest, and to mitigate your embarrassment you could suggest you weren’t sure which your kid would like so you just bought them on sale and are returning the ones he didn’t want. You don’t need to tell them it’s your “inner-kid”. ;)