OG did an evaluation of the Mars SP-250 over here:
Not knowing the model number, a $500 price tag per unit sounds like a considerable mark-up. If you consider them, order direct. Experience has been that they ship fast.
They do have a somewhat checkered past based on their last generation models. Time will tell with their newer models. The SP-250 appears to be a decent fixture for a small space. Multiples would be even better.
Lighting, while expensive, is one place where it’s worth the extra research and spending a bit extra for quality units that’ll last over time, are safe, etc…