I almost can't believe I'm writing this considering how much I complain about some PDFs being too expensive...but this is way too cheap.
I picked up the subscription to the 3.5 Burning Sky, and I was amazed at the level of quality of the product. And how cheap it was!
To make new/old subscribers happy, I suggest giving a coupon to those who already have it to get it for the current price, and then raising the subscription to $75 or even $100. And charging at least $10 for the modules individually. Maybe $12 - $15.
Why do I say this? Because I have an inkling of how much work it's going to be to update the product to
4E, and I want you to actually have a return on that money so that you'll ever consider doing this again. I started updating the first few mods to
4E for my group, and it was a lot of work.
For those people thinking about picking this up: coming from someone who has the earlier edition, and who would have run it if not for the appearance of
4E, go get it! A lot of the pacing for the modules will work better with
4E than it did for 3.5 in my opinion. The Burning Sky series is every bit as good as the best adventure paths put out by Paizo, and far better than anything we've seen from
WotC.
Mind you that's in my opinion, and your mileage may vary and all that...
--Steve