It sounds to me like your pdoc and his office want you to show up

I would not pay a whole lot of attention to the $300 charge, it's a little like the car insurance "vanishing deductible" you get for not having an accident; you only pay the deductible if you have an accident so having $100 subtracted from nothing does not cost them anything but sounds good; they just have to charge you a mere $8.50 more a month than the other guys (and there's really no way to "compare" rates one company to the other, the rates are based on the individual company's experience with accidents in your neighborhood; one company may have a lot of people who drive poorly in your neighborhood whereas another company may have fewer, so not have to spend as much money) and they'd get their "vanishing deductible" back if you had an accident. If you get your deductible down to "zero" they'd still keep collecting the extra $8.50 so. . .

Don't be late and/or call and cancel/change appointments appropriately or get notes for legitimate excuses (many people have to get notes from doctors for their work, "prove" they are sick) and it becomes a non-issue. If you don't like the thought of it, find another doctor whose policies you prefer? I don't think the amount is that ridiculous; when they see you, they are prepared to see you; if you do not show up they still have to pay their staff who will, presumably, be doing "nothing" and reorient their schedule, etc. It would be an additional handicap to them, causing work for "nothing".