Tax class costs $200 and they say you're not guaranteed a job, even if you pass it.
Pay is based off of the number of tax returns you did the previous year; so one year you could be making minimum wage per hour and the next year, you could be making a few dollars more (although there are bonuses at the end of tax season if you did enough returns and sold enough products). The next tax season I'll be making almost a dollar less per hour than I did last tax season.
As more people are taking advantage of doing their taxes online for free, less people are coming in to the office and sometimes it's very slow. There were days during the last tax season (2015) where no clients came in at all.
You are expected to sell additional products, some of which aren't very good.
There are no set prices; cost varies depending on the complexity of the return. Many clients walk out when they get to the end and find out how much it will cost them (average is between $100-250 for my returns). You are required to do their taxes even if you know or feel like they'll walk away when you get to the pricing page. The tax return isn't submitted to the IRS until they pay - they can walk away at anytime, so your time is wasted and you could have lost the opportunity to serve a paying client.
Some offices are competitive because of commission and bonuses, which causes some tension and conflict, especially during slow times.