well, checking ebay, the only place I can find used copies of 1st ed in hardcover (which you specified in your initial post) the starting cost is $63, and has to be shipped from the UK. 1st ed was a 200 page book, and all in black and white. (also the edition in question is the one Mongoose published, which has some questionable quality control issues). if you want a NEW copy of 1st ed, you would have to settle for paperback from drivethru.
Revised, from Drivethru, is $60-80 (the difference between the 2 is color quality, but I'll be damned if I could tell the difference), is a brand new book, so it doesn't have any mysterious stains that aren't reported, and is a 310 page book with a bunch of options that were in the 1st ed's suppliment line, and shows how Kevin has grown and learned as a game developer since he first published SWN1 (his first game I seem to recall) as well as having some nice bits from his other games as well.
So, if you are JUST looking at the cost, you should get the POD revised $60, it has a greater page count than the original edition, a binding quality you can count on, and comes with a free copy of the PDF.
as a side note, I have around 50 PoD books from drivethru, and I've only had an issue with 1 of them. the first 48 pages were only printed on 1 side (making 24 pages of info) and the next 16 were blank. Drivethru couldn't have been nicer, and after I sent them a couple of photos showing them the printing error, they sent me a free replacement copy via express mail.