Keep your options open when it comes to audio. It is not the brand that decides the overall sound stage rather the individual components. It also matters what kind of amplifier it has. Most of the subwoofers come with Class D amplifiers. These days the sub woofers come with state of the art BASH amplifier. You may consider its frequency range that it plays say 25Hz to 180Hz, how lower and deeper it goes, cone material (paper, polypropylene, kevlar, aramid fiber, aluminum etc.,), etc.,
I had various sub woofers in my mind say Polk DSW550i, KEF C4, Polk 110, Taga TSW 200, Taga SW 10 v2.0, Emotiva BasX S10, S12, Velodyne Impact 10, 12, Space Technologies Power-FL12 (all are fit in your budget).
But finally settled down with BIC Acoustech PL200. I have never heard much about BIC but after reading lots of reviews, I finally went for one. My room size is 10 X 14 not a big space at all. In my setup, my sub woofer is very powerful at 2/10 volume points and fills the room. It neither distorts or produces any port noise. Being a big sub woofer does not mean it would be louder and harsh. It would be going deeper and tight when it plays any LFE.
My suggestion would be, don't stick with a sub for its brand rather be open and listen to various sub woofers and pick one. I would vouch for mine because it's worth for its price, packed with solid construction, warranty etc., I have been enjoying its cinematic experience (Yes, it sounds like theatre). Ask for opinion and input, everyone here would be happy to help you!