tigerdirect.com has an xbox 360 for $249.99, is this site reliable?

I am not aware about that site.
If you want to know if a company is legitimate,you should keep in mind the following instructions
1.Use Whois lookup tool like Whoisxy.com to check the whois information.Because legitimate company properly update whois database.
2.Then check whether domain owner contact details and E-mail address is currently active or not.
3.Finally take some reviews about that company using Scamadviser.com,Webutation.net.
I am sure above the steps are very useful to check any company is legit or scam.I hope it will be very useful to you