'Fred'(Linda B.)has it just right! I am not a pro, but I HAVE been doing my own minis for 22 years, and I shod my own QH a couple of times around 30 years ago(out of frustration at not being able to get a decent farrier in the little AZ town we lived in at the time...)-and, have trimmed my own 'bigs', including a mule, a few times in the intervening years. I would say that doing mini hooves 'should be' comparable in both time and difficulty, all else being equal,to doing 'big horse' hooves--and I darn sure wouldn't want my horses done by anyone doing 50 in a day! It is true that some minis have feet like IRON-and additionally, that the sole on some grows down with the wall, adding to both the challenge and the difficulty of doing a proper and safe trim. Hoof trimming, not to mention shoeing, is VERY hard physical work--and yes, there are MANY whose horses aren't properly trained for having their feet worked on. Are there 'bad' farriers...yes, I've seen some sorry work over the years-so you need to look for someone with good references from other KNOWLEDGABLE horse people! Though I think it possible that a farrier might be willing to charge MODESTLY LESS to TRIM a mini than to trim a 'big', all things being comparable--you usually DO 'get what you pay for', even though theremay occasionally be an exception to the rule(some years ago, I 'got' one who thought he was God's gift to the world, charged MUCH more than others were, at the time-yet really wasn't very good-he didn't come here but a couple of times...). I have a great guy now(I do have a 'big', and I do have her shod, for about 8-9 months of the year)-Frank is a GENUINE cowboy, but knows his stuff, takes his time, does a good basic shoeing job. GOOD farriers darn sure earn what they make-and in these times, you should expect that they will have to charge more, due to the nature of their work.
I have often had mini owners wanting me to 'show them how to do their own'. Once upon a time, I did--but I don't anymore, as I have seen too many who really don't know enough, go right ahead--to the horses' detriment! (An area owner, a 'newbie' to horses, period, comes to mind; she went to one Martha somebody clinic, and right away, she trims her own--next I hear about the mare she recently bought and bloody feet--makes me just CRINGE....!)The first thing you need is a good EYE, to SEE hoof angles, whether a hoof is level, whether the heel is too high, the toe too long, etc., etc.--and most 'lay' people do NOT have, and honestly, can not seem to develop, this vital ability, FIRST(even some otherwise competent farriers, in my observation, seem to have a problem with this, doing minis--I have seen this any number of times, and have no idea why it would be so....???? (The second thing you need is a really good set of TOOLS, and a conservative,non-hurried approach-again, not something many 'casual' owners are willing to opt for...)
BTW, GOOD farriery tools are not only expensive, but some are VERY SHARP, and must be handled with proper protection(leather farriery apron, for starters), and proper caution.