Beginner dslr or secondhand D300?

I've looking to buy my first dslr, I've been looking at the Nikon d3200 and the d5100. I also have the chance of a Nikon D300 second hand for £400, is it worth me investing in the better build quality and model, although this is quite an old model now, or do I stick to the quite cheap and cheerful beginner set-ups? Any advice much appreciated. The d300 has had very little use.