It’s really easy to find out Huawei 3G routers at low cost on Ebay for example, but most of time they are simlocked.
Happily, you don’t have to call the cellular operator to unlock it, you just need to know that tool :
Click on http://www.bb5.at/huawei.php and type IMEI code you can read on the battery slot.
Be carefull typing, the code isn’t validated only characters number. Click on calc button to show a page with 3 different unlock codes (it depends on firmware version) and a flash code (if you need to change that firmware, what I don’t know recommand).Connect your brand new sim (from another cellular operator) et swith on the router. Connect it by wifi using wpa code, if everything is ok, you should see on your browser a page asking unlock code.
You just have 10 tries..
Link : http://www.bb5.at/huawei.php