I really half agree/disagree with both of you.
The name's not worth nothing for two reasons.
1) There are enough people out there who have incredibly high expectations for the .mobi extention (borderline crazy) that he could quite easily sell today for the mid to upper $xx range to another domain farmer (especially inexperienced ones) in an auction.
2) It's quite likely that the .mobi extension WILL catch on in a few years' time(mobile Internet will become quite popular, so long as the prices come down). However, I don't believe they'll be quite as popular as TPSchaffer does. It's just crazy to believe that this particular domain name will sell in the mid $XX,XXX range. Even if the mobile web becomes popular, desktop Internet will still vastly dominate the market, and as Marcel pointed out, lawyers are not the typical thing people will be looking for on their mobile browser (I'd guess maps, dating, sports, news, and video will be the key areas of interest). Myself personally, if I'm looking for a lawyer, it can wait till I get home - there's no immediate need to look for one on my cell phone's awkwardly small screen.
Anyway... my own price valuation:
Now: mid $xx to low $xxx
3 Years from now: mid $xxx - mid $xxxx, potential to get to very low $xxxxx, but only if everything goes terrificly in your favour with the growth of mobile web and the .mobi extension, and you get extremely lucky in finding the right buyer... I'd put low $xxxxx in the less than 1% chance of happening category.
You might also try selling to Aboutdomains or TPSchaffer... if they're so confident in their price valuation of $33,000+, they'd probably be quite interested at the prospect of picking up the domain name for a measley $20,000 investment (I suspect you might be happy giving it up for that price).
Hope that helps,
Pavel