I want to purchase vBExperience

Is it possible to buy it for 15 euros?
37 or something smilar is way to much

It's actually called vBActivity pro, and currently costs €25 for a 1 year license. We have no plans to lower the price any time soon.

You might want to try following our twitter channel (www.twitter.com/dragonbytetech) as there are occasionally offers/discounts available exclusively through the twitter feed =)