Surely it is relative though. If you take even the most basic villa and compare it against a bargain basement motel the villa is quite clearly luxury accomodation.

Luxury is your problem word, in that it is subjective, rather than an objective measure.

If a home was advertised as having a 60" widescreen TV when it only had a 32" widescreen TV then this would cleary be a breach of the TDA. If it was advertised as having a huge widescreen TV then the 32" set would be fine. Who's to define how big a TV has to be before it's huge?

Anything subjective is, by definition, just that. Subjective.

Even the Mercedes might be considered far from luxury motoring by someone who has just bought a Maybach.