Can anyone know how the baggage allowance works?

I am looking at the BCN/VCE flights on Vueling and IB. Then I notice the flight offered on IB works the best with us timewise, is a codeshare of ClickAir operated flight. IB allows 1 free piece of luggage on economy up to 23kg. I know ClickAir charges checked luggage. The same flight is offered on IB with 55.85 Euro all in, while on ClickAir is 30 Euro before checked luggage fee which wont show until you fill in all the passenger info. I dont understand why IB has such Odd number of fee (the breakdown of fees show strange numbers with cents.)

Should I book on IB site for the codeshare or book directly with ClickAir?

Which terminal ClickAir flights leave BCN?

Thanks for responses.