Well guys i have some info about accommodation: there are two places selected after the search, the other places are very expressive.
In this location all places except one discardted, are in the outskirts and they are to some extent far from the place we're going to do the EE meeting.
1-
Hostal Avenida Madrid:
This place has a discount 20% if we're hosted 3 nights or more. The shared bathroom is referred to a bathroom for two rooms.
Double room with bathroom 50 E /night (3 night or more 40 E/night)
Double room with shared bathroom 40 E / night (3 night or more 32 E / night)
Single room with bathroom 35 E (3 night or more 28 E / night)
Single room with shared bathroom 25 E ( 3 night or more 20 E / night)
This place includes: heating, air conditioning, television, Internet access (wi-fi)
2-
Pension Lorenzo:
I think i understand what the guy told me (Arab foreign accent) but only sure 90%, the prices are as follows:
Double room with TV 40 E / night
Double room (no TV) 30 E / night
Single room with TV 24 E / night
Single room (no TV) 18 E / night
Both places are free to the 8th-10th July dates for the moment, i'll wait one week approx. before i confirm reservation.
In short, the first place is only a little more exprenssive (if we stay 3 night or more) but it provides some aditional services, the second place is cheaper but not too much if we think in spend 3 night or more there.... if it is not the case .... and you're looking acomodation for 1 or 2 nights the second one is the better option.
In my particular situation i'll spend 3 nights sure because of my transport combination to return home.