First, one would need to define "bargain" in some tangible way.
Next, you are comparing retail prices of components vs the price of this iMac. Conceptually, you could price out every bit of almost anything and make the mass-produced alternative a "bargain". For example, I'm drinking out of a plastic tumbler. I think I purchased it at Walmart for about $4. Is that a bargain?
If I wanted to argue that it was, I'd could price out what the plastic would cost, what the molds would cost to make, what the glues would cost, etc. In the end, to make one from scratch vs. the mass-produced one I have, the latter would certainly be a financial "bargain" as I'm sure I couldn't make the same for less than $4.
In building the iMac, Apple isn't paying retail for the various components and then offering it at a generous discount. They are getting all those parts at aggressively-negotiated prices. They are not paying manufacturing costs for just one built for OP. Instead, they are mass producing these and thus getting all kinds of labor economies. And so on. If one tries to build an equivalent from scratch, the price of this can probably be viewed as a "bargain."
In common use, getting a "bargain" is usually implying that the buyer somewhat managed to put one over on the seller: "at the bankruptcy option, I got a bargain on this _________ because it was XX% lower than what it would cost at retail"... or "I got this ________ on sale at 50% off retail. What a bargain!"
What you get with this iMac is Apple's full retail price. You're not beating Apple's retail- just paying the full price they want for this product.
So it is a bargain? Again, define bargain. To make paying full retail a "bargain" one probably has to flip the definition into a subjective perception of value for the money spent. Do you think you got good value for the money? Apparently you do. If so, your definition of bargain might be thought of like that... a substitute for a perception of "good value".
In my own case, I've still got a working iMac purchased in 2010. I consider it a bargain because it is still fully functional and helping me make money as a business tool even though I paid more than this $1999 price way back then. Here, I'm bending the definition of bargain (too) by associating it with longevity of service of this tool. I'm (also) substituting the word bargain in place of "value".
In short, I think nobody gets a "bargain" out of paying full MSRP for anything. However, I think many can get a "good value" out of this particular product, especially if it can serve them well for many years to come. That's just my own opinion based upon my definition of "bargain". Others will certainly differ.