A sealed booster box of the Skyridge expansion, the last set to be released by Wizards of the Coast, just sold on eBay for $6,599. This is at least a 25% jump in sale price compared to the last auction of a Skyridge booster box, which went for less than $5300 (the exact sale price is unknown) in November, 2017.
While no other sealed Skyridge booster boxes are for sale on eBay at this time, individual booster packs, priced at $200 each, are available. 36 of those will run you more than $7000.