I just got
A shark RSR2. I know it's out of your price range but if you can find something with the same visor on (RSI may have it) then I'd strongly recommend that - it's cracking. If you're buying now I'm assuming winter use is on your list of things to do so a visor that sheds water and won't scratch when you wipe crud off it is essential.
Shoei do a budget hat within your range as well. Don't know enough to recommend or not.
Avoid Arai. Like the plague. Fine for summer, leprotic, black bollocks for winter.
Unfortunately you can't just have two hats and go for the one that people say is best - it took me about a month of hunting to find a hat that fitted properly (even then I needed different cheek pads). Fit is the most important thing so go out and try on a load of hats, get the people in the shop to tell you if it fits or not and make a list of those which fit.
Then come back and ask opinions and google some reviews.
Also, make sure that any shop does not try and sell you a display helmet - it MUST be new out of the box. If you dropped a £400 hat on the floor, rendering it useless, would you admit to it or would you quietly put it back on the shelf? Also, you don't know what has had it's head in the display one.
It's all about fit - a £30 hat that fits will protect you better than £1,000 one that doesn't.