It’s quite possible (and likely) that the iMac Pro is not something you need, therefore it appears overpriced to you, but it is not. It is directly comparable to the cost of the components alone if you were to buy them today.
For those of us who need this type of machine to do our work today, it is a very good value. I work deeply in multi-cam 4K 60fps projects and occasionally with Red 8K footage. I am always on a tight timeline and 2 hrs saved in a day in the editing room is a huge boon for me. This doesn’t make me special (if people only knew)...it just means that the iMac Pro is right for me and a lot of others at this point in time. Again, your needs are obviously different and that’s ok, but the iMac Pro is not overpriced for what you get.
Everyone needs to buy the right tool for the job.