Cheapest phone tarrif

[Bongtrees]

Does anyone know the most cost effective plan to use with
a normal land line, well 2 actually and no chance of ADSL or RDSI(?) as too far from exchange (10kms).

Is it cheaper to use telefonica for the equipment and another company for the calls, is so which company is best (cheapest)

Location close to Valencia and not yet found anyone providing satellite system that works.

TIA

Mike