Those numbers are referring to the Pay Per Click competition... Not the organic side of things.

So high PPC competition can mean a more valuable phrase, but it doesn't exactly mean that it is a more difficult phrase to rank for, organically.

You could use something like Market Samurai, OpenSiteExplorer, Long Tail Pro or one of many other tools to help you identify the organic competition if that is what you are after.

[DELETED]

If you want to monetize your site with Adsense and you are looking for keywords that will trigger lots of relevant Adsense ads, then choose the ones with high competition.

But if you are looking for keywords for which you can rank pretty quickly and easily in Google, disregard the competition tab in Google's keyword planner and focus on the strength of the top 10 ranking sites in Google for that keyword.

How to assess keyword competition: Keyword Competition – Keyword Research: The Definitive Guide