I'm a long term Oly 4/3 user, and have had E510, 520, 620. (Full declaration: I used to get given them by Olympus) Now M10.
The E410 is a serviceable camera and uses Olympus glass which means it is capable of really good results. Compared to modern cameras it is likely to feel slow and its low light performance will be suspect. Up against an equivalent Canikon, you would likely see not too much difference, IMO the degradation in low light performance is more than made up by its better performance in general use with lack of fringing etc. Also, again IMO, the Olympus "access all areas" menu system makes it much more versatile than the competition (if you can see it, you can change it).
Would it be worth £50? Hard to say, depends what you expect for your money and what else is available.