Does it bother you that no reputable dealer sells these?
Nope. 
The WS2803's smaller variant the WS2801 is used in many a pixel addressable RGB LED strips so is not necessarily a hobby device. As for 'reputable dealer', I'm no longer prepared to pay there 'reputable' prices if I can help it. My first 2x MAX7219 chips from Mouser cost more than 10x 'Buy It Now' MAX7219 chips from a 'eBay Top-rated seller'. My first obligatory Arduino clock project would have been about 25%-30% cheaper if I had thought to use eBay first. 
The TLC5940 is a good chip but for me it's a bit more expensive (from eBay) compared to the WS2803 and the 18 outs of the WS2803 suit better for RGB LED's compared to the 16 on the TLC5940.