This is all just my personal opinion on what I would feel comfortable with. I'm well aware other people won't feel comfortable with the same things I do (some would want to get more/pay less, some the opposite), but I'm not writing this to start any arguments about it, just to hopefully throw another data point that might help the buyers should they succeed in buying.
I had all vet rewards and would like to get them back (at least the useful powers and the coolest costume pieces). I would even be willing to pay again for the priviledge, although not as much as they cost the first time (say, a package with them all for $25-$30, maybe even $40, I could easily part with, much more and I would start feeling bad about it). I would not mind terribly if I had to play without many of them either.
I had bought many (but not all) of the packs with costume pieces (including those useful powers like ninja run). Again, I would like to get them back and wouldn't terribly mind paying a reasonable price for a package with most of them again, where a reasonably price means lower than I paid the first time (I'm thinking maybe the same $25 to $40 dollars tops for that). Some characters NEEDED some of those costume pieces to exist (my lion-headed, armored, titan weapons tanker for instance).
I had bought every powerset that had been released, and many of them I had not even had a chance to try yet. This would be the MOST important part for me (since many of my characters used the paid for powersets and many of the characters I had planned to play with in the future would use them). Again, I would pay for that (even before I paid for the others), but bear in mind that this is the THIRD item we're talking about that could cost $25-$40, so we're talking a total of $75-$120 here, which is not pocket change. The total of $75 for everything I had before I could see myself spending with a bit of trepidation, but mostly as something useful that would also be a show of support for the buyers. The total of $120 increases my trepidation a lot, and decreases the likelyhood I'd buy them (although, of course, they could have the individual packs be more expensive, and launch an everything pack at a discount I guess).
I never stopped paying a sub for the game and don't foresee I would stop if the game came back, so I, personally, would not mind not having those rewards that improved my non-sub-paying experience. If the sub managed to include access to those things I talked about before without me having to throw money at them (powersets, vet rewards, costume piece/power packs) I'd be very, very happy. If I paying the sub at least allowed me to get them at a discounted price, I'd be happy too.
It would be great getting the character data back, but I, personally, would still gladly play the game even if that did not happen. What I liked most in CoH was making and levelling new characters. I had at least 2 whose level only had one digit when the game shut down that I wouldn't mind at all starting from scratch with, 2 or 3 more in their early twenties which I really wanted to play and who would take me only a few hours a piece to get back there, and at least 6 characters I had planned but never made. So I have aproximatelly 10 characters I would gladly start from scratch with that could keep me happy and busy for quite a while.
If we DO get character data back, I just hope we ALSO get a lot of total character slots (not necessarily slots per servers, but slots times servers), because I had 51 characters by the time the game closed (28 incarnates, 23 which I wanted to get there - some more, some less). Sure, I could certainly pick and choose only some of the incarnates I liked best and some of the most promissing lowbies, but it would be a bit painful. I had gotten some extra slots as vet rewards and from the store, but I'm not sure I would buy them again too soon even if, at first, we had few slots. I would pick a handful of incarnates/lowbies and leave some slots open for new characters and go from there.
I'd miss my old characters, sure, but I do have their Sentinel+ data, screenshots, demorecords, MIDS builds etc. saved to remember them by (some of it is in
http://www.drgamma.co.nf/ )...
What would worry me most about getting the game back is the auction house. If we did not get character data back, I'd be poor again (and I hate playing market games to get rich soon again, not to mention all the other currencies my characters had). And if we DID get the characters back, people would have money to buy things at inflated prices, and there might be a lack of recipees (even common but wanted recipees like Thunderstrikes were hard to get back then, imagine now) and other stuff for builds. It would mess up my planned builds some, but I'd still love to have this problem to contend with. And, hopefully, drop rates could be messed with in the start if the market started being a problem...