While there may not be a lot of differences between monitors at first glance, there are several reasons to go with a business class monitor opposed to a inexpensvie, local open box deal at your closest retailer. Most consumer grade monitors while they seem like a great deal, will have a lot of problems months or even years down the road. The main problem with consumer grade is that most are built to only be on around 2-5 hours a day, opposed to business grade which are built to be on 16-24 hours a day. Commercial grade displays from leading manufacturers such as NEC, Samsung or LG are designed to dissipate heat and use higher grade components to act more reliably during the more intense usage. As that consumer grade display continues to run it gets hotter and hotter thus increasing the likelihood of failure.
Ontop of that when (not if) you run into a problem with your consumer grade monitor, your warranty is most likely up. While most manufactures have a 90 day warranty on their product, if you read the fine print most companies state in their warranty that if you bring your consumer grade monitor into a business setting then your warranty becomes void with the company. Business class monitors typically come with a 1-3 year warranty. The last thing you want to do is set up your whole office with monitors and have them all fail. Prevent the problem and consider a business class monitor instead.
Furthermore, a vast majority of current monitors on the market come with sub-par accessories. Most of the newer business class monitors come with height adjustable stands that can also swivel to adjust your monitors however you would like them and whatever feels best for you. Business class monitors also come with more ports on the back of the monitor, allowing you to connect as many as 6 separate devices to your monitor, and also come with higher resolution ports such as HDMI and display ports, allowing you to have higher resolutions and better graphics on your monitor.