Keep my bridge camera, or get a DSLR?

Last year I bought a Fujifilm SL300 Bridge camera (£200) for my holiday, now looking back, I regret buying that camera, and what I really an DLSR. I have looked around for ones under £450, and the best one I found were the Nikon D3200 (£400).
If you were in this situation, what would you do? Keep the SL300? Sell the SL300 and get the D3200 for £200 more?

First you'll be fortunate to get £50 for your Fuji. Used bridge cameras aren't worth very much because they're so cheap in the first place.

I'm a Canon guy so that's what I always recommend however Nikon makes excellent cameras and you can't go wrong. But don't expect to sell that Fuji at all unless you already have a buyer. Second when you do sell it, you'll still, most likely, have to pay another 350 for the Nikon.

If you know you're going to take photography seriously, sell the SL300, and get a DSLR.

If you mainly post the photos on a social media, just to share with friends and family, keep the SL300.

You need to know if you like using a DSLR before buying it, and knowing about photography helps too (rule of 3rds, leading lines, etc).

Keep the bridge camera to play with, and buy the D3200 for more serious photography.