2000 Reg Focus CL - Noise from rear bearings (Again)

I have a Ford Focus CL and has 37,000 miles on the clock and in great condition generally. I have just this week noticed a noise coming from the
area of the rear bearings and have been advised by a "mechanic" to have the bearings renewed. All he did was ramp the car up and give the wheels a quick turn by hand. He said the noise told him "all he needed to know". I never heard that much of a noise to be honest, so how do I know if I really need this job done? It's going to cost me 240 (UK) to get the bearings done, is this a good price for this job?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.