I'm also very new to the CM franchise and have slightly differing views about both the price and the games being the same.
I own CMSF2 (plus all the DLC's, flavour packs or whatever you want to call them). I also own a number of the WW2 titles, CMBN, CMFB and CMFI, again with all the add ons.
One thing, which IMHO you are missing in your assessment, is that these add-ons also include additional campaigns, maps and scenarios in addition to their vehicles, regiments and weapons etc.
There's both large and subtle differences to all of the WW2 titles I own and there's simply no comparison with the WW2 titles and SF2.
I'd also spin the "Price tag too high" remark a bit different. For sure I needed to think hard about dropping my money (I'm on a fixed income these days) on these titles. However, in the end, for me at least, it came down to "Value" rather than "Price".
I play a lot of games, from many different genres but ultimately I enjoy sims, war, strategy and role play genres and all the better if some overlap each other.
I've spent $$$ on so called AAA titles and had no more than 10 hours in to them before I'm bored and move on.
I've spent $10 on supporting indie dev games in early access over a period of years and I've spent literally hundreds and hundreds of hours on these titles, often getting what amounts to a new game every few months as the dev releases updates.
Then there's the Paradox titles as an example, that are not "cheap" to buy but offer me, as a player, real value in terms of the hours and hours of gameplay that with DLC's add to and alter the games over the course of a decade in many cases.
When I evaluated my expense on my new CM titles that is how I looked at it. Yes, it was a large outlay in terms of cash, but seriously, I knew I'd eventually have thousands of hours in to those titles over the course of the coming years.
Price? Not for me, it's about long terms value and I'm more than happy with my decision.