This practice is absolutely standard in oscilloscopes (which is what I'm right now shopping for). Additional options will set you back between a few hundred or maybe a thousand dollars/euros easily.
In the past "options" were actual PCBs to be installed, or swapping out of pricey components/subassemblies.
But software options are typically "only" things like being able to decode i2c/spi/canbus/... from acquired traces or calculating a fourier-transform.
Also on the lower end models (where it doesn't make sense to build additional hardware, because even the relatively cheap amplifiers and ADCs will be able to do a few 100MHz or few GS/s) scope bandwidth might be artificially limited when not purchasing a software option. Some vendor also limiting the amount of used sample memory intentionally.
Heck, some scopes cripple their memory capacity which can be unlocked with a software upgrade.
Curiously, Rigol, a test equipment company, recently updated their dirt cheap line (DS1052E to DS1054Z). The DS1052E had a notoriously weak software option unlock encryption, so hobbyists bought the 400 dollar scope, punched some code into it generated with some Javascript on some webpage, and bam, you got a 1500 dollar scope.
Funny thing is the DS1054Z has the same exact issue. The crypto on the 1054Z is also crap (http://gotroot.ca/rigol/riglol/ yay!) -- some have even speculated that they do this intentionally because they know corporate people won't hack their scopes, but hobbyists will, furthering their brand in a market filled with American competitors (Keysight formerly Agilent, Tektronics, etc)
So how is this different to selling a computer and then selling software for it? Obviously the computer would be capable of running the software already pre-installed...
1. These are generally hardware drivers rather than generic software. If your computer comes without a text editor, anyone can provide your with one for whatever price they decide. If your oscilloscope comes without an I2C decoder, no-one else can add it.
2. Usually the software is used to cripple the device and then you pay to remove it. For example on oscilloscopes they use a software low-pass filter to limit its maximum frequency. You can pay to have it removed.
You know, I bought an R&S 50MHz mixed-signal scope that had the ability to software upgrade to 100MHz. It's more expensive than the Rigol, but the UI is miles ahead of Rigol as well.
Anyway, I was pretty happy with it and used it at 50MHz until one day I needed the extra speed to debug a higher speed glitch. Quick call to my distributor, pay a couple hundred bucks, and I instantly have a faster scope on my bench.
Part of me is grouchy that it was just a product key to type in, but honestly, I have a great tool at a reasonable price point and I didn't have to pay for the extras until I needed them.
Could I have just hacked it? Probably. But I'm making money using the thing, it's a tax writeoff, and I don't mind paying for well-made equipment.
In the past "options" were actual PCBs to be installed, or swapping out of pricey components/subassemblies.
But software options are typically "only" things like being able to decode i2c/spi/canbus/... from acquired traces or calculating a fourier-transform.
Also on the lower end models (where it doesn't make sense to build additional hardware, because even the relatively cheap amplifiers and ADCs will be able to do a few 100MHz or few GS/s) scope bandwidth might be artificially limited when not purchasing a software option. Some vendor also limiting the amount of used sample memory intentionally.