I split up with my girlfriend a week ago and the relationship ended on good terms I got a text from her saying she was going to throw my belongings away (woth £200) if I didn't go to her house and collect them by Monday (4 days) I work full time and don't regularly go into the town where she lives but she drives past my house 4 times a week anyway to go to college and could have left the bag outside my door if she was that desperate to get rid of them. I told her on Tuesday that I'd be able to get to hers Wednesday to collect my things and she told me she already threw them in the bin. Is 4days enough notice to expect me to collect my belongings? And do I have any legal rights regarding getting my money back?

Short and sweet, nope sorry, there is nothing legally you can do here.
Basically you chose to leave the items with her, so she can dictate what happens with them.

I'm curious - why would someone break up 'on good terms' and yet leave his belongings behind? And how does a whole week go by with not even one day off from work to go get them? And lastly, how could you not have seen this coming?
Anyone can sue anyone, and you can certainly get all your receipts together and try, but you clearly and admittedly moved out, so what you left is abandoned.

Obviously your breakup was not on as much good terms as you thought.

The problem you have with filing suit here is proving the value of the items. I think the time an expense of pursuing a suit is just not going to be worth it.