I couldn't find what they're currently going for. Make sure you talk to James or a couple of other guys before picking that up. It's certainly in a 50/50 depending on condition in my mind. I can only find a sick one (non-booting, but starts up) for $30 on ebay. I found some weak SE/30s (missing sound, failed floppy drives) out on ebay for $10-15 right now, but I think those are exceptional finds.
I figured shipping would be a problem - but as a macquarium it's not worth as much to this crowd. I was just hoping to get you a general figure. Sorry it turned out to be a bust - unless you really like macquariums.