Tax and exchange rate!
''All previous Studio One™ Professional versions to Studio One™ 6 Professional Upgrade: $149.95 USD''
Be a lot of people downloading from non-EU sites for the 150 USD price which will probably be discounted down again by some of the better online shops
Crazy that it's the same cost top go from V1 as it is from 5...skipping a few versions is really where the value is.