What are PPC spy tools?
These are basically tools that allow you to understand what keywords and ads others are bidding on so that you can make an informed decision whether or not a PPC campaign is profitable.
Are PPC spy tools worth investing in?
Most of the spy tools found in the market I don't use because while some take 30 days to give you results, others crawl keywords and ads that don't give you real time results. By the time you enter the market, the competitor may have left the PPC market for that keyword. In other words, you might be entering a market that is going to lose money. The keyword that we thought was a gold mine, no longer a good keyword.
For now, if you're planning to be a PPC trader, manual checking is still a good idea. Find the niche you enjoy the most and this will help you be motivated to do the research required.