I feel the more expensive DI poxes like the Radial and Countryman and really worth the money in the long run. They sound noticeably better and are very durable. However, it's also nice to have a couple of extra boxes around, and I have to admit that my spares are a Whirlwind imp and Director. They are substantially better than the cheapo boxes by Rapco, etc. and are close to the price range you mentioned.

I picked up a barely used avalon u5 for $300 and never regretted it. It has a big but very transparent sound