It's legal, and depending on what state you're in it might even be mandatory. Many states are what's called "community rated". This means that the insurance carrier goes to the insurance commissioner of the state and says, for such and such a plan, this is what we're going to charge for a 27 year old, this is what we're going to charge for a 42 year old, this is what we're going to charge for a 36 year old, and so on. Once the rates are approved by the insurance commissioner, that's what you get charged, period. Whatever your census shows (in your case, just yourself) that's the only thing they can charge you. Although community rating is great if you're a small company with high medical increases, it can be a problem if you're a small company that doesn't use the insurance much, because the rates the company designs and presents to the insurance commissioner are based on the entire community rated pool. I've seen increases as high as 400% because of community rating. Community rating is only for small groups, but what each state interprets as a small group varies. I've seen it as low as 3 employees and as high as 100.
If your state does not community rate (and I didn't cover Ohio when I worked for an insurance carrier, so I don't know if it does or not) then there might be some wiggle room for you to negotiate the rates down, but if it does, you're stuck and nothing either you or the company can do will change them. Your state insurance commissioner can tell you if your state community rates or not.
Thanks again.