so whats the actual price for yamaha vintage collection ?

for example vintage stomp is 99$ or euro , is this the price after the 50% discount or this should be 50 on checkout ?

Vintage Open Deck is normally 199.99Euro so 99.99Euro is the offer price.
I think that is the only one that is on offer. According to the email I received anyhow.

I know probably is a stupid question, but … are both the vintage collection and vintage channelstrip 64 bits AU/VST versions?

Yes, both are native 32-bit and 64-bit plug-in versions.

VST 3 or AU host required on Mac and VST 3 or VST 2.4 host required on Windows.