Thank you for answer! Yep, I'm moving to ovh because you pay for channel, not for consumed traffic. Ovh has a load balancer, but for 0.5pb per month it will cost you 15k. Data is mostly outbound. Haproxy will help until the channel is not saturated.
EDIT
I've checked linode pricing, their lb has a flat fee because it includes 2tb of traffic :)