That was a huge mistake, low competition keywords are often the worst keywords to put into a PPC campaign. There is usually a good reason the competition is low, those keywords are either too ambiguous and/or reflect no commercial intent. Typically, adding those types of keywords will harm your account level Quality Scores and force you to pay higher CPC prices on all your ads.
If you are using a regular AdWords account (not AdWords Express), then you have complete control over your bids. So, you can bid at whatever price you want. Having said that there are many things that will affect the amount you will need to bid to get the amount of traffic you seek.
First and foremost is the proper account structure. How you organize your account can make a huge difference in your CPC. If you do not optimize the structure of your account you will have to pay much higher for clicks than your competitors.
Have you checked your Quality Scores? Poor quality scores will force you to pay much higher prices for the exact same keyword ad slot than your competitors. Improper account structure is one of the main causes of poor quality scores among new advertisers.