Lads Holiday!!! AmsterdamWatch
For places to stay - I loved Bob's youth hostel. But there are tons of great ones - just do a search here: https://www.hostelworld.com/ (has reviews etc).
I went on the National Express but P&O ferries are pretty cheap (from £40) or book a flight using Skyscanner. If you're flexible do the month view and it'll show you cheapest dates and times to fly.
You can go to Amsterdam on the Eurostar too but that tends to be the most expensive option.
On the plus side it does have beer vending machines and weird fast food shops where they have the burgers in indvidual windows with sliding doors. Bit like the red light district but for food. Get good deals if you look at Ibis hotels. I stayed in a mint hotel called The Rembrant (as in the artist-check the spelling) Hotel and it was dead cheap.
Oh right OK. Well we want an abundance of clubs and bars, where everyone is of similar age (18-23). My searches had shown me the Leidseplein area. Said that it was meant to be around a euro a beer in some of the hostel bars and surrounding clubs???
More like 10 euros a beer. I didn't find a single place for less than £3 a pint.
Do not go expecting cheap beer. Do go expecting loads of cool museums and sex shows. There is certainly plenty to do.
Prague is pretty cool, beer there cost between £1.80 and £3.50 a pint. Budapest was about the same, although the nightlife was a bit patchier.
Budapest is cheapest probably, although when I was in Amsterdam I spent about £20-£25 per day so I don't know where this £200 a weekend figure comes from. (Wasn't exactly on a lads holiday though)