You'll get answers for and against. The big time investors will tell you to build a team of agents to find the properties for you, so you can focus on building your business. Furthermore, I've met plenty of people that take that approach and are very successful.
I, however, can't imagine investing without access to the MLS. Sure you can get basically the same listings by searching realtor.com, trulia, or the other sites. But those sites won't tell you which properties are pending, won't provide private remarks from sellers, and, most importantly, won't give you any true MARKET DATA other then the listings themselves.
The MLS has a massive database of information from price reductions, listing history, days on market, etc etc. Seriously, you can get lost in the reports for hours. If you want an all-encompassing description of property values in your area, there is no substitute. Yes, it may cost a thousand bucks to maintain MLS access each year, but you should easily be able to make 1 or 2 retail sales to cover the costs.
As for the course itself, for a couple hundred bucks you will certainly get an overview of the entire process but, just remember, these classes are for RETAIL agents, and they often touch only briefly on RE investing. (My instructor was full of "investing generalizations" which, half the time, were dead wrong or misinformed. [You know, the "you'll be fixing leaky toilets at 3am" type]) Instead, you'll be inundated with RE terminology, selling requirements for cemetery plots, trailer parks, listing procedures, etc.
What's your RE investing objectives? Buy and hold, flips, wholesale? This may determine how beneficial the MLS can be for you. Do a quick search and you'll see how having your license can cause some ambiguity when wholesaling and how to properly disclose that info to prevent any issues.