£80 is reasonable for someone who knows what they're doing.
The rears are really easy even for a novice, however the front is a little more difficult, you will definitely need the proper tools to do it and a mate to help is always handy. The hardest thing is removing and refitting the front struts, they take a fair bit of manoeuvering about. I used a crowbar to lower the front wishbone slightly to align the bolt holes with the strut.