Hi Richard
A few years ago I bought the Clarke bds model that is quite similar to the Warco above, and other 'hobby' types like that, which are around the £100 mark. On mine, the non standard motor that was made to fit in the casting, behind the circular sanding disc, only lasted a couple of years and I ended up scrapping the machine. Other than that it was not too bad to use and I got a lot of good work out of it, Maybe I just got a wrong-un, but I would not get that type again.
If I get another I will get one where the motor is a standard size and type and easily replaceable.
Steve