The prices should be listed on the website. I know the concept is the same in the US as it is here in NL. You pay per month. You get your "free" trial period and then you pay either monthly or quarterly (I'm not sure exactly). But the prices should be very clear on the website
There are thousands of food and drink listed in the database. It's quite cool actually and a great way to plan ahead and keep track.
Here in NL I pay €14,95 per month. A great investment in ME if you ask my opinion