Apple II Rev 2 value?

I have a rev 4 Apple II in the 38000 s/n range. I'm hoping to, over the years, gradually trade my way up to a Rev 0. I've seen Rev 0 units go on ebay recently for around $3000ish. Below that seems to be a jumble, mostly to do with completeness, originality, etc. Although, no always. Some have had motherboards upgraded to newer versions and still gone for $2500. Anyway, I'm looking to move up. My questions (and I realize this is all opinion): 1) What would my Apple II rev 4 be worth? Again it's serial number is in the 38000 range, black label. It was in France and had its original board replaced with a clone board, and some customization including a small switch for power that was drilled into the back of the case was done. I have installed a Rev 4 board with Integer Basic chips. I also did some repairs on the keyboard and it is fully functional, but the repairs involved a couple of jumper wires to deal with bad traces. 2) What would you be willing to pay for a 12000 range s/n Rev 2 that is in so/so condition, some rusty chip legs and non-functional keyboard? Is a Rev 2 anything special? Thanks!