I found this: https://www.ovh.co.uk/domains/prices/ that offers .es new regg for about $4. OVH.CO.UK seems only for UK residents. Any other sites that offer for that amount or lesser?
I can confirm: Not for UK residents only
OVH.CO.UK is such a good provider but it's quite complicated and will take time to register. You will have to prepare to be verified by ID card or credit card photo.