some are, some are not. That is a make of rifle, not a model.
100-300
From my experience, BRNO rifles are very nice. They are no longer made under the name BRNO, but CZ, and although the manufacturing processes may have changed, the CZs are near identical to their BRNO ancestors. Try to get a BRNO model 2.
270
10-1000 USD depending on specifics
Blue book of gun values
Assuming you mean a Brno 602, it will depend on the caliber that the rifle is made in. Brno 602 is a make and model, not caliber.
.270 WCF means Winchester Center fire. Yes, same round- and IMHO, one of the best rifle cartridges ever made.
No, .270 wsm and .270 winchester are not the same.
It's the caliber of the cartridge it fires.
.270 is the larger calibre of the two.
You will have to contact the factory.