I changed my headunit last week. Had the same issue as yourself, I didn't feel the need for better sound quality, just wanted a working headunit and in addition I wanted integrated bluetooth since I do like the option of using the phone while driving.
I got a Blaupunkt Helsinki headunit which actually looks just fine and not at all out of place and it only cost EUR 99 (that's around 78 quid I think) brand new.
Installation was easy (apart from one stubborn ISO plug on the back) and I have never before installed a stereo in a car. The phone mic works really well with perfect connection. No SatNav I'm afraid. Sounds just fine and dandy.