Like was said earlier it depends on pricing.
Legal copy, that is a great scan and bookmarked.
Sure I might jump on quite a few of them.
Poor quality looks worse than if I do it myself, yeah probably not going to bother and is probably already on file somewhere in my library of files.
My only reason for buying them is to support the actual process of it, showing my interest in this product and those editions.
Everyone in many threads recently has been asking how can WotC make money from prior edition folks.
The short answer is they can't.
Every single one of us has moved on and found another way to support our chosen edition.
Long answer is they can, but it's dual edge for them.
1. Supporting the older editions doesn't earn the newest edition money, but the money that is generated is money that might not have come in to play anyways.
2. Pirates, yes most of it is already pirated, most those of us who would have a pirated copy already do. Future pirates cut into our profits. Again this is an age old arguement, pirates will be pirates now and into the future.
3. How deep do you take the support?
Do you bring it into the DDI fold? You bring it there, you might get more subscribers just for that.
Do you bring it into a character builder? Good lord you might make money on that alone.
But no matter what, its going to be an accountant that looks at it:
Does doing X make more in sales than it takes to create X?
As long as WotC can answer yes, than you have a fair shot at it.