Catchy promotions in the cosmetics store - are they real?

Hi there!
Today I would like to go back to the world of cosmetics. More precisely let's talk about the promotions that had place few weeks ago in a really popular cosmetics store - Rossmann. Every 3 to 4 months this shop is offering a promotion which is working like that: when you buy 3 different  make-up products, you will get 55% off your purchase. Doesn't sound amazing? 
One time, I read an article that this action isn't that great. Why? Before the promotions, the prices of make-up are being raise so when the promotion goes life it seems that we are saving a lot of money, which is not true. Yes, we are saving SOME money, but it's not that much that we would think. 
Also, there are a lot of online shops that are selling make-up a lot cheaper than in Rossmann. For example a mascara that normally cost 60 zl, online it costs 25 zl. So even with a promotion we are paying more. 
I would suggest doing research and really think if you are saving money. Also, I feel that people buy more make-up that they need during this offer, and they are not able to use it all up and it goes bad. Beside saving money, they lose it after throwing up old make-up.
To sum up, for me this is all a huge marketing. Everyone wants to earn money, so they are trying everything to achieve that. Don't let them to do that and be more conscious that not everything is how it seems. 
Personally I didn't buy anything during this promotion, and I am proud of that. 
Thanks 
Kasia