I don't have any firsthand knowledge if this shrub sets viable seeds or not. However, it is patented which means that it is propagated by licensed growers assexually to ensure they get a consistent, exact reproduction of the plant each time. Seed collection/growing is not prohibited under the terms of the patent but that generally means that the seedlings will not always be true to the parent plant. It is quite possible, give viable seeds, that a seedling from this plant would produce an entirely green leafed plant, for example. This is often the case with the seedlings generated from any named cultivar - they may or may not bear any resemblance to the parent and cannot legally be called by that name.

Personally, I'd rather invest my time and effort and $$ in a small start of this shrub from a reputable nursery if I really wanted one, rather than risk less than optimum results from seed. On ebay, it is always a case of buyer beware.

I have no knowledge about the viability nor how likely the seeds are to come true to their parent, but since the 'Black Lace' does flower, I would assume it sets seeds. So probably the seeds are from a 'BL', but as said above, I wouldn't count on them producing many, or even any, 'BL' seedlings. What you get would, I think, be wildly variable.

Save your pennies and buy a potted start that has come from a cutting - it may cost more, but....

I tried grow the plant from seed and all of the seedlings had the typical full leaf - no lacy disected leaves.

Here is a link that might be useful: The Plant Hunter Blog