Offer, Product, whats the difference?

When i go find my latest camera lens on amazon, i sort things by price. 

And the world now is so transparent, that with a little effort, you can find any product for less cost,

This means the market is not able to sustain the product game, because if you are not the cheapest,

Then what are you? 

Offers, on the other hand, is different. 

i was offered a set of camera lens, with tutorials on how to use them to master them in 3 days, now it shifts from price based, to value based. 

Next time when you are selling somehting, ask yourself, 

is this an offer or a product?