Learn English – the meaning of “chewing the carpet”

The trick to understanding this advert comes at the beginning:

Here’s introducing iDiva: Five Magazines in One

So the publisher is saying their magazine is the equivalent of five other magazines.

Also they are selling the first issue at a cut down introductory price:

At an introductory price of Rs 5 per copy

So, in their mind, the magazine is cheap even compared to a normal magazine, but because it is five magazines in one, the cheapness is exaggerated by that multiple, so this deal is five times better than any normal discount on a magazine, i.e. five times over.

A sorry lot (sorry definition 2, lot definition 4) is simply a regrettable or deplorable lot; so a regrettable group. It is the same as saying a sorry bunch. It could potentially be interpreted as pathetic, but not usually. So you are correct; it means a sad group.

Note that sad does not mean that the members of the group are sad (emotionally), it means that the group as a whole is sad. Definitions 3 and 5 both apply.