I have yet to buy any SSD. But I'd consider paying 20-50% more if I thought a product was of better quality than the cheaper mainstream product. As a total non-consumer of SSDs, I have no opinion of any brand differences in this market.
Small doesn't have to mean unprofitable. Small is a relative term, ie smaller than Samsung or Intel, but that doesn't mean tiny. I'd rather have 6-8 smaller to medium sized competitors, than an oligopoly of 2 or 3. However, this is often the long term outcome. There comes a point where a few big names become entrenched, wield enormous influence over tangential factors, and it's no longer viable for anyone else to enter or compete.