Based on that eBay listing, they are roughly half the price of than the major brands.
It is certainly possible that the hockey stores that already deals with Step could order the figure skating blades. But both the hockey stores and the eBay outlets might be problematical if there is a problem with the blade (e.g., if it is warped), and you might not trust a hockey-only store to mount the blades on your boots.
I also don't see anything about the material composition, or numeric edge hardness. That makes it very hard to guess how durable the blade will be, and how long the edges will last between sharpenings.
Step says each of their blades is comparable to a set of blades from other companies, that differ from each other a lot. So it is a bit hard to guess the Step blades characteristics. Perhaps one could call the factory...
http://www.stepskates.com/en/hockey-blades/goaltenders talks about coating the steel with very hard nanoparticles. Would that make it hard to sharpen? I recall one skate tech telling me that one of the brands of blade that used titanium took about 15 minutes to sharpen. If it was anything like that, most sharpeners would give up before it was sharpened well, or would charge extra. In addition, there are a number of technical issues about how well the layer adheres, and whether a coating on the outside surface of the blade would be all that helpful to maintaining your edges after sharpening.
You say there may be a connection between Step and Skate Science. Interestingly enough,
Gepetto's Skate Shop, run by John Harmata ("Mr. Edge"), one of the world's most respected skate techs, used to sell and advocate Skate Science blades - but seems to have dropped them from their website, and doesn't offer Step blades there either.
Any time you order an off-brand with no reviews from people you know or respect, you are taking a chance. It's hard to guess the result. Personally, I wouldn't chance it for just a factor of 2 in price.
However, if you buy, I'm sure the rest of us would be curious about your results.