"Intervening prices"

[guoguohu]

Dear teachers

What does 'Any intervening prices available on request' mean exactly in a Christmas sale scenario? I have abusolutely no idea at all.

Thanks in advance.
Guoguohu

 

[5jj]

It appears to make no sense. Have you more context?

 

[guoguohu]

It appears to make no sense. Have you more context?

I was in Marks & Spencers, noticing this small print on many 'sales 50% off' boards.

G