Request #1: Please let me have your comments about the guidance I received from my tech.
Yes, I agree. Most decent active pickups START at about $100 for the pickup (I know of 3 sources for the Mi-Si Acoustic Trio that has it around this price), and then unless you install it yourself, you will pay labor to have it installed for you.
Having said that, for the sake of example, if the 'uke with factory pickup' is like ~$150, you are getting a cheap instrument, with cheap electronics, and if you want to gig with this
AND have
decent sound
and reliable electronics, I'd say you are not getting it in this scenario.
A cheap uke may not be braced well enough to handle the rigors of gigging, and cheap electronics may not only sound bad, but also may have minimal shielding and poor grounding (a problem I've encountered myself).
Also, if you are going to have a pickup installed you are going to be asking someone to cut holes in your instrument, and do you want to be installing some cheapo $15 Belcat UK-200/UK-3000T that you ordered from some faceless vendor off ebay that takes 3 weeks to ship from China and has no warranty you can use, or do you want to get something that if it develops a problem, you can get in touch with the manufacturer and get support?
Request #2: If you agree with my tech, please give me your recommendation of high-end electronics that would
be well-suited to a baritone uke.
I have installed the Mi-Si Acoustic Trio in 3 different instruments myself (Epiphone LP concert, Kala KA-T tenor, and Yamaha GL-1 guitalele) and I am very happy with it in each case.
The Mi-Si uses an L.R. Baggs under-saddle pickup ribbon and instead of a battery, it has a 'super-capacitor' that you recharge with the included cable in 60 seconds, that lasts betw 8-16 hrs before needing a recharge.
The Mi-Si does not require a large cut-out hole (there are no on-board controls in the stock version - but you can add the volume and tone controls separately), only the endpin jack hole ~3/8" or 10mm, which is where the preamp sits inside the uke, and then two 2.5mm holes (one at each end) of the saddle slot for the pickup ribbon
I've also heard good things about Fishman and the L.R. Baggs Five-O as well as the B-Band pickups, but have not used any of these myself.
The B-Band uses a PVDF piezo film for the under-saddle element that is about half a millimeter thin, and as such you should not have to route out any slot for the element in the instruments' bridge, and maybe only have to shave a hair off the bottom of the saddle if the action is ever-so-slightly raised and bothers you...
There are also many passive options (all less than ~$70), which also let you use an EXTERNAL preamp, so keep in mind that whatever you choose, you may find it better to have a different setup.
With a passive under-saddle pickup, I've used both dedicated external solid-state as well as vaccum-tube preamps and find benefits with both for different scenarios...but it is more equipment to gig with, more wires to hook up and depending upon an external preamp is not really conducive to just walking out on stage and start playing right away...(like for an open mic night performance)
Hope this helps,
Booli