A *lot* less.
My plan is $83.97 usd/mo with all fees and taxes.
It includes 3000 daytime minutes, unlimited Internet on handset, unlimited hotspot access, and unlimited SMS. It does not include long distance and unlimited nights and weekends airtime as I don't need them (I get 3000 minutes for the price of a 1000-minute "national" plan).
Nowadays, $99/mo is effectively unlimited everything, but fees and taxes add up to more.
I do use thousands of minutes, hence this plan is appropriate for me. Without Internet/SMS it would be $30 less. If I were to use every minute in my plan, it would effectively cost me $0.016/minute.
Get More 3000 plan $49.99
Unlimited Domestic Text and/or Instant Messaging $9.99
T-Mobile Total Internet Add-on $19.99
Total Due Monthly*
If I used less airtime, I'd use an even less expensive plan. Carriers have relatively unadvertised "regional" plans that, in my case, cover calls within California and Nevada.
In my experience, most people to whom I talk are on a wrong plan and are paying more than they could be. It can be complicated to accurately estimate the use. I routinely review my customers' bills and reconfigure their plans to save money.
In fact, I could probably drop the TXT portion of my plan and save some money, but I like to have a set not-to-exceed budget item referring to my cell phone bill.