I have seen something very similar to this before. I was trying to rent out an apartment using Craigslist, and I got e-mails that sounded way to good to be true, and they were all written in the same fashion. They, too, were wanting to send money via Western Union and send too much. These were "doctors" and "family men" trying to rent a 1 bedroom apartment on a college campus. Definitely a scam... I'm not sure what the scam is...but definitely a scam. The form and sound of the e-mail reply you posted is extrememly similar to what I encountered.. don't do it friend