I've done a bit of googling, but couldn't find an answer and was hoping someone could help or point me in the right direction. We run a local 'bricks & mortar' business and look to be the only business in our industry & area running Google Ads. I understand there are many factors that go into the Google Ads Auction, but if we are the only business running ads for certain keywords (literally the only ad showing), why would the bid be, say $1.50 per click v's $0.01 per click?
Even if you do a search and see no competitors, that doesn't mean that there aren't any. There are many reasons why you would not see ads. You should never think there are no competitors. There are a few million businesses advertising on Google and chances are that there are others, at the very least have been in the past. Not just in your area but all over the world really. The system takes that into account when suggesting bids. So even if you truly are the only one in your area, you can't just bid low and expect to pay one cent per click. It doesn't work that way. If you are given a suggestion to bid a certain amount, there's a good reason for it – historical data.
Although if you are advertising local plumbing services and your ads are competing with international businesses then you probably need to double check your keywords.
My best advice to you is use a professional keyword research tool like SEM Rush or another SEO agency that can narrow down the best keywords for you to use with your campaign. Like the one member Lucid Web Marketing mentioned there could still be competition for keywords you would like to use. The best bet is to get a professional keyword research report done and then go from there.
I would say start with a relative low bid like $0.10 and watch it daily with a limited daily budget just to be on the safe side. Then only time will tell if you need to increase the bid to get visibility or if you could actually lower it. The thing is that your ad not only competes with other competitors, but also with the editorial/organic search links. So if Google only see low paying low quality ads, then they would rather display organic links first and put ads on the 2nd or 3rd page.