Dampkring is definitely NO rip off. We bought there some of the best tasting and strongest weed we ever smoked. Even though we dont smoke as long as many others here, but we are smoking dutch-/coffeeshop-weed since some years now so I think I know what I am talking about.
I think I will give you a more detailed review about the shops I mentioned.
Those are not very old as we go every 2-3months for a 1-day-trip to buy stuff and hang out a bit in the real city of god
Dampkring:
Always very crowded, except in the morning-hours. Both of the shops have very very very friendly staff, which will always take its time to advise you the right strain. I remember last time we went to Dampkring 1, the one from Oceans twelve, the guy at the table talked to me about different strains and showed them to me for like 5-10mins even thought behind me there were around 15 people waiting in a row. The last time we went to Dampkring II (Pink Floyd) I talked in English to the guy behind the counter, but after he saw I was talking German with my girl he started talking German with us and was happy he could do so and to be honest he spoke a very good German, even better than the guys working in some border-coffeeshops near to us

The weed is just amazing, whatever we bought there, it was never ever disappointing or not worth the money. Buy the hazes for a crazy high, buy the Diesel for the best taste and the Lavender to set yourself for sleep
Grey Area:
Well, I wouldnt buy anything else than the Chocolope here as it is a very expensive shop, but the Chocolope is so amazing, its worth waiting a bit in the row. The guy at the counter, I think his name is John, is always so friendly. We had gone there three times and the Chocolope was always sold out. This time I asked for it he told me "well, there is a new delivery coming in half an hour"....I didnt want to wait as it was already a bit late and we had a meeting with some friends in Mellow Yellow. I told him to give me the rest of what was left in the box, as I know this is not of low quality but just looks not as good because there are no big buds anymore. He gave it to me for 10€ instead of 13,5€ which is the normal price for it, so I saved some money here, very nice guy and cool people hanging out there! Its worth an experience.
Blues Brothers:
Well.....mixed feelings about this one. Its a dark shop. There are many tourists in it, but the atmosphere was always a good one for me. The weed we bought there last summer was tasty, with the Mango and the Sour Diesel and the prices were not any higher than in other shops, I dont know how people can consider this a tourist-trap, for me this is no! The 2 guys at the counter were friendly even though it was very crowded and they showed us everything we wanted and even helped us to find Dampkring by telling us how to get there(if I remember right

).
Mellow Yellow:
My absolute favourite shop in the Netherlands. The dealer is always friendly. The locals usualy sitting at the window-front dont look down on you or something. Its big enough to get you a seat almost whenever you go. The weed is just great, especially the hazes and the Blueberry. The music is a mix of everything so everyone will feel comfort here as it is not too loud as in many other shops. Never saw it crowded, full yes, but never crowded. I just love this place, its the best place for me to hang out after a day in Amsterdam.
With those shops you cant do anything wrong, I promise you

Buy your stuff there and then you can go to shops were there is cheap weed.
Hope I could help you a bit