One hour min at $200 seems steep for most small gardens.  Heck, it may be a couple passes and 15 minutes of work.  I’d probably look into the minimum being a stopping fee, to load, travel unload etc… and that minimum also cover say the first 30 minutes.  Then have an hourly fee above that.  This way a single pass garden is worth your time, but there is also enough value in it for the customer.  I have a tiller and tractor mainly to till 1-2 acres annually, several times… when I was quoted the cost to till it, it was about $200/hr.  So that’s fair… but making $200 the minimum won’t be a value to most simple gardeners.  And, then maybe it’s also not worth your time to travel there.