I dunno.... That's like a great name but as far as value is concerned I wouldn't buy it.
Brandable? Not really. + it may have some trademark issue.
Keyword value? Yes. But it is a highly competitive terms with a poor extension, so that wont be a walk in the park.
Type-in traffic should be very low.
I would say in the xxx$ but I may underestimate it.
I believe Expireguy (who I haven't seen here in a very long time) sold blogs.biz a year ago or so for low $x,xxx. I'd guess blogger.biz is perhaps in the $400-$600 reseller range. Nice name though.
I sold Blog.biz in Feb for $8,000. Blogger is probably not nearly as good, and I think Phronesis was probably in the right range, mid $xxx. Doesn't help that Blogger.com is developed as big as it is, as one wouldn't have much motivation to try and develop on it while losing significant traffic to Blogger.com. Obviously non .com extensions always face that, but more so when it's a huge site, and .biz doesn't exactly get lots of type-ins.
Sure, I knew blogger.com.tw has been transfered to google, the TM issue is serious, but as for proper use and disclaimers, this issue would be avoided (hopefully)