First, I realize that this question could span a couple of different forums, so my apologies if I'm in the wrong one (but it seems right). Also, I did a search and didn't find the answers to these questions (although a few came close.)

I have a first generation iPhone running 2.0, and have noticed the good prices that people seem to be getting on eBay for resale, so I'm thinking about doing that. Here are three questions I'm trying to figure out:

1. Is there some value to downgrading the phone? (Meaning, is there some reason that a person who will subsequently unlock it would prefer to have it sent to them with 1.1.4 on it rather than 2.0?)
2. Is there a particular difference between me selling it "unlockable" versus "unlocked"? (I know what the difference is, just not sure whether it would make a difference to a buyer beyond convenience.)
3. In order to get the best price for resale on eBay, besides the normal stuff -- being in good condition, erasing all personal data, etc. -- what do I need to know.?

Thanks.