Unfortunately I can not agree with everyone else comments in regards to the EN World Online RPG Store. About 2 or 3 weeks ago I wanted to order some books and e-mailed them to get a rough idea how much shipping would cost. (I live in Australia) After no reply I e-mailed them again, this time I e-mailed it to 2 different e-mail addresses that are listed on the site. Once again no reply.
Finally I posted a thread on EN World in the hope of getting some sort of response. Eventually someone from the store posted on the thread and suggested that I send them an e-mail using the form e-mail on their site. I did that and still didn't receive a reply! I don't know why I never received a reply, I even checked my spam filter and trash can just to make sure that it didn't get filtered out. After all that I gave up. I wanted to support EN World by buying through the online store but I didn't feel safe in handing over my money to someone that a couldn't get an e-mail reply from.
I may just be an exception to the norm but that was my experience.
In comparison I e-mailed FRP Games, Noble Knight Games and Stiggybaby and received a reply from all 3 vendors within 12 hours. I eventually went with Noble Knight Games. Aaron Leeder who runs the site was very helpful, answering my many questions quickly.
The other thing you could look at though is ordering from the company directly. I don't know about Chessex, but Crysal Caste, who I bought my battlemat off of have an online store on their website. I would use them again without hesitation. The owners (the Bowling brothers I think?!) were both quick to reply to my e-mails and answered all of my questions in a friendly and helpful manner. Another bonus with Crystal Caste battlemats is that they come with both squares and hexes, one on each side. That was what sealed the deal for me.
Olaf the Stout