Prices are for a standard double room in high season, without meals. Tax (17%) is extra.
Although the Mexico City is huge and spread out, most hotels are clustered in a few neighborhoods. Colonia Polanco has a generous handful of business-oriented hotels; these tend to be familiar major chains. The Zona Rosa has plenty of big, contemporary properties; it's handy to have restaurants and other services right outside the door. La Condesa and La Roma don't have many places to stay, but at this writing the chic Hotel Condesa was in the works in its namesake neighborhood. The only pleasant tourist areas still poorly served for accommodation are Coyoacán and San Angel.
You can expect hotels in the upper price categories to have purified water and extended (often 24-hour) room service as well as all the standard amenities.
Business travelers tend to fill up deluxe hotels during the week; some major hotels discount their weekend rates. Many smaller properties have taken the cue and offer similarly reduced rates as well. If you reserve through the toll-free reservations numbers, you may find rates as much as 50% off during special promotions.