Concerto, I assume there is no easy way to find the OK tariff on its website. Before (like 2011, early 2012) you could always see the fare once you did the booking from your OKP account.
Now I mostly book via the company travel agency where I see the fare in the T&C of a chosen flight.
As the work-around, you can book the ticket on-line but at the payment stage you can just cancel the payment (back to e-shop function) but your reservation would still be valid. You get a code and you can either call or email CSA to find out your tariff:
Phone #1: +420 239 007 007
E-mail:
[email protected]
How you pay that later or whether you have to pay a service fee - I can't tell now.
You are right to assume that U tariff is likely to be the cheapest to give the segment.
Hefty surcharge you may face is, likely, due to revenue maximizing techniques (offer just Plus and Flex fares by default) employed by the call center. Otherwise, you may ask for a specific fare and just pay a 30-40E service fee on top.
I'm Gold (ST Elite+) with CSA OKP since 2008 (Plat in 2011) - can tell more of recent experiences. Program lost lots of its perks since 2010 and acquired little from flirting with Korean, Etihad and AF-KLM.
Cheap 320s used on most of ex USSR destinations give so little comfort in business...