Bryan you are right to be concerned. Although I have not heard anything bad about these guys there are a few red flags.

First off these guys are not The China Network as someone else has suggested.

These guys don't seem to have a website and while that is not the be all and end all, it is something that I would be wary of. If they are really serious about their business then they really need to invest in it to build confidence.

They seem to be based in Guangdong but are offering two positions in Shanghai. I have no idea how they operate, but generally speaking you are best to deal with a recruiter who is actually in the area that you want to work in, otherwise their value is somewhat negated.

The salary being offered is about double what most middle schools would pay and that seems suspicious.

You are in contact with them already so you probably have nothing to lose from pursuing the deal but be wary.

Don't pay them any money. Don't sign a contract with them. Don't rely upon this job as your only opportunity and reason to travel to Shanghai.

Do ask to speak with current or past teachers at the school? Ask those teachers to send you some pics of their classrooms and the school - everyone has a digital camera these days or can access one, but someone who is not at the school but pretending to be will not be able to come through on this.

Finally let us all know how you go. Be sure to report your experience here as well as at www.buxiban.com so that other teachers will know in future.