Tough to say Bob, I am a small one man LCO in bus for 6 years and each job has different requirements. Your example is for 8 man hours at 31.25 per hour. Not bad but it depends on different variables. I personally do not bid on a per hour basis but I do have a minimum charge of 20.00 as some of my customers lawns take me 20 minutes and some take 2 hours but the variables are the key. What I mean by variables is , is the job a job that you want, will the job get you other jobs, will you be able to sell additional services, can you easily fit the job into your route, and do you know what your costs of business are amongst other variables.
Each area of the map is a little different as to what the market dictates so I can't give you specifics on price but I can tell you not to bid mowing on a per hour basis to the customer. Measure each property and look carefully there may be lots of trimming or special requirements that can sink you. Communication with the customer is a great part of your bid. Figure out your cost of business and from there you can get started.
There are many more wiser than I here and I highly recommend reading many opinions. Good Luck - welcome to Lawnsite.