I find the ride on my Fiesta (2011) to be on the soft side. It's fine over sharp edges but feels a bit bouncy over long wavelengths. One of the rear shocks has a slight oil tide mark (not significant enough for an MOT advisory) but I doubt whether it is contributory. 

www.onlinecarparts.co.uk have Sachs, Mapco and Monroe shocks between £33 to £40. Although marketed as direct replacements I was wondering whether anybody has replaced lightly worn originals and can offer an opinion about whether anything changed.

I think you may be surprised at how little it takes to make a shock absorber have adverse affects on handling.

When I bought the mrs car, I went to view it and test drove it - absolutely spot on. Went a week later to pick it up, on the way home on some twisty roads i could feel the back end dancing a little on the road and it really did feel odd. So I was pretty confident it was the rear shocks. Upon inspection I could only see a tiny and i mean tiny amount of oil on the shock shaft. Bouncing the corners of the car I could see one of the rears took a while to slow down the movement. Got the mrs to drive it while I followed in my car, sure enough, one of the back wheels was bouncing like crazy!