Points and counterpoints:
1) I agree, price does make a big impact. This may be the one reason it takes longer to sell out
2) "Ultra limited" is a bit of a stretch term, but I'm sure Zavvi would apply it if the print run was 2,000. Again, I think this will take a while to sell out, but I don't foresee a price drop in that time.
3) The "old" steelbook wasn't available worldwide to many people at a decent price, certainly not us here in the U.S. The few retailers that did sell it were HMV, some Amazon sites at ridiculous prices, and some Asian retailers.
a) This new steelbook is superior in every way to the awful first Martian steelbook (minus 3D)
b) We don't have any details on embossing/debossing/finish
c) LAH is a must-have for Schwarzennegger fans. I re-watched it recently and found it too long and uneven. Not a bad movie, but not in the same category as Terminator 2 and Predator. The Martian is a must-have for science, space exploration, Ridley Scott, and Matt Damon fans. The Martian has an 8.1 rating on IMDB while LAH has a 6.2. The Martian was nominated for seven Oscars. As a kid, LAH was always (to me) the movie that heralded Schwarzennegger's downfall. Its appeal is a bit limited. The Martian has a much broader appeal. I am pretty confident that I'll still be talking about it in 10 years, probably 25. If you doubt me, read the book, which is even better than the movie.
Points (a) and (c) are the main reasons why the steelbook will sell out in good time at the price it's offered at.