Personally I like Borka and fix-it and use both regularly, so I don't have a dog in the fight but I don't see quite the price differences you're talking about. I paid $161 for my fix-it-stick kit with 5 limiters at DVOR (
FISTLS11-T kit + 49 inlb), or $32 each if you don't count the other stuff in the kit. Honestly to me the big limit with these type of limiters (ha!) is that they are fixed, what I really like about the new Borka is I can easily set whatever torque I want in small increments in one package. The fix-it-sticks are only handy if they have the exact torque you want. If I wanted a full fix-it-stick kit for all my gun needs I'd need 4/10/15/18/20/25/30/35/40/45/49/55/65/80, and somewhere well over $400. With my kit that only has 5, it only works for some of my gun needs, which was another big reason to add the Borka as a field/range kit, because it offers way more torque range. Fix-it-sticks are a bit quicker to use, and I like that I can put them in any of my 1/4" bit handles/tools, but I also wonder about their accuracy, I know the Borka kits are accurate.
I looked into those products you mentioned and they not really cheaper, certainly no where near half.
Let's take the Silca: First it's $100 (I've seen the fix-it for $43), second it's graduations are MUCH more coarse and I'd never want to use it for gun applications, you only get marks ever 1nm, that's every ~9 in/lbs and they flip flop from side to side meaning unless you go from looking from one side to the other you can only see 18 in/lbs between very closely spaced lines. The Fix-it-stick version there is 10in/lbs between marks but you can easily cut that in half visually if not 1/4's. So getting 2.5-5in/lb increments is easy on the fix-it-stick and basically impossible on the Silca. That said I think they say it's only 10% accurate so I'm not sure cutting it down to 2.5 in/lbs is within their accuracy error anyway. Third you have to use silca's T-ratchet handle as it won't fit into a standard 1/4" socket so you can't use it with any of your tools and it's only available in a full kit. To me the fix-it stick version is about the same price as a kit, but you can get just the unit and use it with any 1/4" tool handle you already have.
SILCA T-Ratchet + Ti-Torque Kit + 10 s2 High Vis hex/torx/phillips bits + waxed canvas carrying case - - Amazon.com
www.amazon.com
Pretty sure Neither Borka or Fix-it-Sticks were the first people to invent a long shank hex bit, they've been around for decades.
I looked onto the Sloky torque limiters, because who wouldn't want the same thing for half the price. Except they're not. The two places I could find selling their sets, which once again are the wrong torque values or gun applications were $200-$300. The $200 kit at amazon only had 6 limiters so that's $34 a limiter, and you can get fix-it-sticks as cheap or cheaper. Worse yet their values are: 5.3, 8.0, 10.6, 12.4, 17.7, and 26.6 In-lb.
Sloky STS-IP-LT-S1 Preset Torque Screwdriver LT Combo Set Torx Plus Size IP6-15 (13 Pieces) - - Amazon.com
www.amazon.com
The Toepeak Nano you mention is $80 for 3 torque limiters, which admittedly is only about $27 each, but they also are not useful torque numbers for gun use. I will say I like their handle design, esp. for a compact field kit, but it's hardly half the price of the Fix-it-sticks.
I do agree they've probably copied other kits/tools in that they've taken what's worked from previous products and either offered the same or similar things. Not sure how I feel about this, in the cycling industry it's been happening for decades because every company under the sun offers a bike tool kit and they all basically have the same tools.
Don't get me wrong I think lots of shooting stuff is overpriced. We have people paying $800 for a bipod, $200 for a muzzle brake, $500 for a scope mount, $400 for a AR handguard, $1500 for an aluminum chassis with plastic skins. $1800 for a tube and some baffles for a supressor, $1500 for a tripod, $325 for a AL plate with a picatinny rail to track scopes, etc. As long as customers can't wait to line up and to toss their around on hugely overpriced products there are going to be companies happy to oblige them.