Hi Rob
2nd hand Canon 55-250IS is within range of your budget.
Nifty Fifty
Canon 40mm "pancake" lens...
A few options, but might be easier if you gave an idea of what you were thinking of - if you were ...
Is that ebay second hand £70 jobby?
Not fussed about focal lens realy want to have quality of image and I do hear you get that with the nifty fifty although which one is the plastic one?
Don't worry about the silly stories and all that's written about the 50mm being made out of plastic. I'm not sure about everyone else but I don't use my lenses to drive nails in or drop them all the time.
I loved the 40mm pancake lens and its much better quality than the cheap 50mm.
Also over a stop slower! Unless you really need a tiny lens I can't see the point.
it doesn't wear well and is given to falling apart under heavy useage even without being dropped etc.
Spend the £100 on something else if you don't know what lens to buy, there's no point buying something for the sake of it. Maybe buy an older manual focusing prime lens if you fancy something to muck about with.