UK Domain hosting and registration company Internetters (which I personally am unfamiliar with) is offering a rather significant discount of 50% on .ES domains (the country code top-level domain - ccTLD - for Spain) throughout October.
There are no restrictions on the volume of .ES domain names (although the discount will only be applied if there is one full price domain purchased). Keep in mind that the discount only applies to the first year of domain registration; subsequent years will be charged at the standard price. Apparently the deal is not available for renewals or transfers either.
A spokesperson for Internetters commented: "We are constantly working to achieve great results for our customers, from providing great discounts on domains as well as fantastic web hosting deals too. We currently sell a variety of domains, including the .ES country code domains, which are highly popular at the moment so this is a great time for people to buy them cheaply".