hi mate!
i paid £40 for the rear beam from ford salvage in barnsley, south yorkshire (im very lucky, got ford salvage down road, my uncle owns a scrappy and my brother works at a car auctions and knows all the major breakers in the area). most people pay around £70 - 80 for them i believe. my uncle has the focus 2.0 rear brakes, but i havent taken them off the car, these usually do about 120 quid on ebay (with the stub axles, which you will need). you then just unbolt the rear drums (and drill the two rivets out) to take the drums off (which are quite large actually). then i believe you just bolt up the focus 2.0 stub axles. i will let you know when i do it and any problems i encounter. in the meantime have a look at the topic i have started (https://passionford.com/forum/viewtopic.php?t=197247) where i have written about what i did.