I can't work out if........................

[ChristmasTrulyReigns]

"Save up to half price."

is a grammatically correct sentence?

Every time I see this (or similar) my pedantic heckles prickle, but I can't explain why it sets me off.

No, it's nonsense. You can save up to half the price, or you can save up to 50%.

Ooh, that's a whole other issue, Euphemia!

Save £100s actually reads 'save one hundreds of pounds' which doesn't make sense at all. Gah!

Really gets my goat, that one .

I'm with Jux and Fellatio, you need the definite article to stop 'half price' being meaningless of 'half-price' being an adjective. I think.

And whilst we're on the subject - not strictly a Pedant related thing in terms of grammar - but '50% more free' is very misleading isn't it. It sounds like you are getting double the quantity for your money instead of half of the original amount. My mum always falls for this.