It took me a long time to ask this question.
I am primarily a guitarist, though I've also played bass for 20+ years, and I went through several different set ups before I realized that your speaker enclosure does make a substantial difference in your overall sound.
Case in point; I currently have both a Carvin 4x12 cabinet, and a Mesa 4x12. Just in terms of the construction, the Mesa is 13 ply birch while the Carvin is 9 ply poplar. The Mesa is also 3" taller, and 3" wider. The Carvin cab has their Celestion Rocket 50's in it, while the Mesa has Vintage 30's in it. Both cabinets sound good, but for different things. The Mesa has a much warmer and tighter sound to it for the ultra heavy drop tuned kind of stuff, while the Carvin has a better lead tone. The difference in price? The Mesa is more than double the price, and is in fact only about $100 less than buying the X100B 100w tube head, and the matching Carvin cab.
Just for the record my current bass rig is a Carvin BX1500 rack mount head and a BRX10.4 Neo cab. I really like this cabinet and it is relatively cheap at under $600 new. It is a 9ply birch cabinet with a serious sub port, and it handles my 6 string basses with ease. If memory serves correctly it goes down to like 25hz or so. Pretty friggin low.
In answer to your question, it is unfortunately a yes and no answer. As you can see the build and design of your cabinet makes a big difference, but then again there is also paying for a name. A well respected name (and therefore expensive) didn't get there over night. There is usually some degree of quality there. However, some manufacturers are a little over the top with their pricing.
The best advice I can give you when selecting any piece of amplification is to let your ears decide. Bring your amp head and bass, and plug in to as many cabinets as you can find. Foget the logo and sticker price. Just close your eyes and listen. When you find one that sounds good to your ears, get that one! Whether it says Bergantino, or Beringer, it doesn't really matter. Even if the price for the one you like is a bit high, or out of budget, it may still be worth the investment simply because you will know that you have the best cab FOR YOU, and will stop looking for a replacement. This in the long run can save you thousands in replacing amps when the issue is really the cabinet! Trust me, I've made that mistake a few times.
Well thats my dos centavos and I hope it helps in some way.
