orbitmic

But some fares can already only be offered with specific points of sales. It happens with many promotional fares and is not illegal. In fact the whole point of the EU legislation that the OP is - in my view erroneously - thinking of is that precisely when a service is purchased in a given EU Member States to be "consumed" in another, the prices and conditions that apply are that of the point of sale (back to the Polish plumber being able to work in the UK under Polish conditions).

Conversely, short of imagining a given EU Member State suddenly implementing the rules that exist in a handful of controlled economies in third world countries that rates for plane tickets or hotels are different for local residents vs visitors* which would seem extraordinarily unlikely, or short of imagining some arbitrary control by the UK government which would restrict what UK residents can purchase from abroad (which is, admittedly, less extraordinarily unlikely), there should be no issue in your average Liverpool-based FTer being able to purchase a plane ticket from Istanbul, Cairo, or indeed Madrid or Prague under the local conditions.

* For the sake of comprehensiveness, MS are allowed to seek exemptions relating to territorial action - this exists when it comes to subsidised ferry pricing for residents of some Mediterranean islands visiting the mainland for instance.