Off the top of my head, the rates are as follows:
All rates are per person per hour (? may be off by $0.50):
Mon-Fri 11am-5pm: $6.00 or $6.50? (1-2 ppl) $5.50? (3-4 ppl)
Mon-Thu evenings, Sun all day?: $8.50 (1-2 ppl) $8.00 (3-4 ppl)
Fri-Sat evenings: $9.50 (1-2 ppl) $8.50 (3-4 ppl)
There is also a 2 person minimum during busy hours, which are evenings and weekends. They also have Power Play on weekday afternoons, from 11 am to 5pm for $26. I don't know if that's per person, but you can have up to 5 people for Power Play.
I've played there before they moved there from Uptown, when the place was Corner Billiards. I liked Corner before, and I like Amsterdam better now. Nice clean place with a lot of tables (for a typical poolhall, especially in Manhattan) that are well-kept. Good bar with some cute bartenders.
The wait times during the evenings and weekends are definitely due to the location like VKJ said, with NYU playing a bigger role than many people think. Corner had a lot of business from NYU students, and Amsterdam picked up the business when they opened. Also, on weekday evenings, there's league play, which can take up to 2/3 the tables.
It's expensive, but I like it.
Fenris