I checked the $100 price tag for 3rd edition vs. 2nd. Someone guessed the four books are around 400 pages total and I can't see them being much smaller. If they turn out to be smaller, than this comparision will be inaccurate.
WFRP 2nd was 251 pages of rules, 4 pages of props, and 1 page of ad for $40. You another 127 pages from the Bestiary for another $30 dollars. 378 pages of rules total. If you throw in the GM Kit for an extra 32 pages for $15 you get 410 pages and a GM screen for $85.
If 3rd edition is at least 400 pages long, the price looks high. But those 2nd edition books don't include 30 dice (which one could argue weren't needed for 2nd edition) and the extra cards you will get--30 careers, spells, talents, party sheets etc. If those extra cards contain game info that isn't duplicated in the books themselves, you might be looking at another 30 pages of rules in card format.
And that price doesn't include the dice. 30 dice cost about $30 (which again you wouldn't have needed in 2nd edition). Or the other bits some GMs may or may not use.
So, if the books are at least 400 pages and the careers and most cards are not repeated as rules in those books, the price is about the same between 2nd books and 3rd edition books and 3rd edition also gives you 30 dice and extra bits (but no GM screen, I figured the character sheets are about worth one GM screen).
If the 3rd edition books are smaller than 100 pages each or duplicate a lot of the card info, then the deal might not look so good. But right now, it looks like quite a bargain if you use most of the extra bits (markers, stand ups, locations cards etc.)