Costco has seagate backup drives on sale. If you open the enclosure they will fit in ps4. They are also usb3.0 so probably works with xbone as well.
2tb is 85.99
http://m.costco.com/Seagate-Backup-Plus-2TB-Slim-Portable-Hard-Drive-with-Case.product.100137371.html
1.5tb is 69.99...