Those prices are ridiculous. My local gaming store still has it on the shelf for around $85.
The joys of the free market economy. People are willing to charge whatever they can, and some people are willing to pay whatever they have to to get what they want.
While the original Core Set is a great deal, at least the vehicles and squads it contains are available separately. The Operation Blue Thunder campaign was re-released in the Tile Set. That only leaves Sigrid and Joe as unavailable except in those boxes still floating around.
If I can find another, I'll probably pick it up, but once you have one Sigrid and Joe, the rest of the Core Set quickly becomes better purchased separately. Six squads is $90, and four walkers are $100, and the walkers in the Core Set only have very limited weapon options. You lose the Steel Rain and Lothar variants, and need to scrounge other parts unless you want to stay with one each of the Pounder, Hot Dog (or two Mickey's), Ludwig, and Luther. Official dice are nice, but you can use normal dice, or dice from the Revised Core Set, and there are tiles available in other boxes.
I'd love to see them release Sigrid and Joe some other way, as that would probably take a lot of price pressure off the remaining Core Sets, and let people buy them while still having money for other DUST models.
I'd also like to see the Revised Core Set light walkers released separately. I have less interest in duplicates of some of the Revised Core Set squads, but would like more of the walkers to play around with.