IMO (street prices, new)...
$299 and under = entry level
$300 to $799 = mid-range
$800+ = high end
I agree with this but let me mod it a little
$299 and under = entry level
$300 to $799 = mid-range
$800-1500 = premiere quality
$1500 + = high end/boutique level
You could gig all day with a bass from any price range and the truth is 99% of the audience won't care what you have and what your sound is......you can get a passable tone out of even the most elementary of basses and it will work for most situations. Will more expensive basses be easier to play and provide unique tones yes!