As a Type-A/Perfectionist personality
I may be a little biased on this subject, but heregoes...
The Zen:
As frustrating as it may be to have to spend time setting up, adjusting, and maintaining a brand new (or a new-to-me) tool, I can not help but to think of this as an essential learning experience. The time and effort one invests in these tasks imparts an intimate understanding of the tool that I don't feel simply reading the manual (or a book) could ever impart. If one never took the time to setup the tool then it becomes difficult to know when something is genuinely, albeit subtly, wrong with the machine.
Think of it as something of a rite of passage with respect to admission to our *ahem* distinguished club we collectively call 'woodworking'.
Granted, an invidual who missed out on this process (or ordeal, reader's choice) will still be able to determine there is something wrong with the motor when it goes up in smoke one day. But will they understand why their jointer has suddenly, one day, begun cutting tapers because someone slightly, likely unknowingly, dislodged the outfeed table by a mil or two. Perhaps even more importantly, an individual who never took ownership for setting up and maintaining their tool(s) is unlikely to have the necessary tools and jigs needed to verify proper setup -- both for regular maintenance and for double-checking setup when concern that some setting may have drifted arises. Is such an individual going to happily fork over the $100+ if the "WW Guy" concludes the tool is setup just fine (and we'll assume that's correct for the moment) and simply tells the owner that their technique must be flawed? (Remember, the "WW Guy" is an expert in setting up and maintaining tools, not a master or teacher of their use.)
The Business Argument:
Keep in mind, also, that $100/call is unlikely unless there is a huge mass of such customers in a small and concentrated region most of whom must have need for only small jobs. More likely would be a per-call/visit fee (to cover travel) plus an hourly charge of $50-100/hr (experience is seldom cheap). Some jobs are an hour or less, but other jobs can take the better part of a day to work out, so low flat-rate fees would require a lot of 15-minute jobs to offset the jobs that take hours to complete. Then we get to the multiple-visit jobs when a tool has a bad part -- one visit to identify and order the needed part, another visit to install and recheck tool setup once installed. Just getting all the cosmoline cleaned off and out of a large tool takes a good deal of time.
Add on to that insurance costs (auto plus both personal injury and property) to protect both the owner and the "WW Guy" should something go wrong (dropped cast iron wing, back injury, etc.). If they amass a large parts and supplies inventory then that also adds more to their operating expenses. Depending upon where they live and whether they are in a corporated (city) or unincorporated (county) location, then they may also need to pay for an annual occupational permit (business permit) which may be either a flat fee or a sliding scale based upon volume or industry. Of course, there are the usual taxes to deal with. I don't know what sales and use tax reporting is like in NC, but here in SC it is a nightmare -- each county, local option exceptions, over age 85 exceptions, and reservation exceptions each of which must be independently reported -- if you travel or ship to in-state customers (Florida, on the other hand, is a breeze to file and report and would only require quarterly returns from such an owner/operator -- you report only by applicable tax rate (in 0.25% increments) for each purchase with food items as the only exception (not per county, city, exception, etc. as with SC)). The complexity or simplicity of reporting and compliance with respect to applicable taxes will also enter into the fee schedule. My best guess is that you would probably have to pay an installer at least a few hundred dollars to justify the travel and time involved to setup a new tablesaw from start to finish.
(Please focus on the business side of this question, let's not get into a debate on the merits of taxes.)
Another way to think of it all: Just think of how much we often spend just to have a tool delivered. Now consider the last time you had to have a car towed to a mechanic -- which did you spend more for -- the tow truck or the mechanic's labor? Now consider that you are hiring the mechanic to come to your car instead, which also means having to transport all the necessary tools and equipment. Mobile mechanics exist, but you generally pay a premium for the added convenience.
The Alternative:
All of this said, If you make it well known to the NCWW community that you need help with setting up a new tool, or modifying an existing tool, you will likely find that some member near you will volunteer to assist. Especially with proper incentive. 
ccasion1 Reminder: Don't forget the requisite photos -- you will be reminded that without pics it did not happen!
My health does not allow me to travel, but if anyone in my area of Anderson, SC ever needed a hand and could bring the tool to me, I'd be more than happy to help them out so long as they realize that I have to take a lot of breaks and overheat easily (even in A/C), so I set no records for speed. :wink_smil I already have all the tools necessary for most any job and my incentive is pretty cheap -- just pay it forward, no alcohol required, as I much prefer water.
Just my $0.02.
