I would say from a business school model stand point to save your money.
But, on the other hand there isn't much innovation right now or anything really exciting out there, so why not?
While I do think the SL iron from the 3 -8 has merit, convincing the general golf public isn't going to happen from a smaller company. I think if you are going to do it, to get your product out now and if Cobra DOES push the single length you already having a modicum of these will lead those to you who want to give it a try and being that you already have an iron in the fire, you could ramp up production immediately. If it is inevitable that Cobra is going to do this and I think they will, the time is now.
If that SL player were to win something, they would go through the roof, because it would have to be the clubs, right??? wink!
Targeting the tinkerers and club building shops could do well. I would build a 5-8 set of SL irons to try.