This suggestion might be a tad un-mustachian... Most bike friendly cities have good small, local bike shops with experts to figure out the perfect bike for you. With your budget, you will have no problem finding something right. The advantage to most of these shops is often they offer lifetime free maintenance (brakes, chains, gears, etc), which if you're frequently riding 9-18 miles will be a good thing to have. Sure, you can find something on CL, hope it's the right size, type, etc, do all the repairs yourself, but this is one case where I think the value of having local expertise that you can call on, largely for free, whenever, could be worth it.