If your goal is to get as good at golf as you can, then, bang for buck, a series of lessons, spaced not too far apart so you forget what to work on, but far enough apart that you properly spend good time practicing the changes you need to make
If it's just really social golf you play and you're not that fussed on the standard of the golf, am guessing that a waterproof jacket might be a good idea over in the UK! Or maybe one of those new Cleveland 588 rtg wedges!!!
I just put some dollars more to that amount and bought a new driver and a new set of irons, so that's me done for a spell.
Only thing I can think of is a new 5 wood although I'm still in love with my current or thinking about a low lofted or adjustable 3 wood for days when the driver is naughty