Did anyone ever get a system to work? I have one that is stupid simple and seems to work on most troops choices. Of the troops choices that I have ran, that are off, are only off by 1-3 points. Only 3 are off by more than that, 6 for one(gretchin) and 7 for the other two(Genestealers and Hormogaunts). The Gretchin end up in the negative numbers, and the nids lose all those points in the gun(as they don't have one).
I have not figured "upgrades" to a unit yet, and have not yet done jump infantry or bikes.
I use a Base Cost of 5, and the Stats of an Imperial Guard Platoon member with a lasgun. Every point up(except wounds) raises the cost by 1, and every point down lowers the cost by 1. Weapon range is done on every 6" for a point raised or lowered. You multiply the number of wounds with the base cost to get the final cost(for those few multi wound troops choices). There does not appear to be any effect for special rules in the units cost. Case in point The Dark Eldar Kabalite Warriors and Wyches did not work until I removed the 3 points for the non existent weapon Strength, at which point it worked perfectly. Another note I always use the "best" number on a stat ie the 4+ save for the wyches in place of their base 6+.
Please run this to try and break it. Please note it has only been run on troops at this point, other slots probably use different modifiers due to the more specialized nature/needs of those slots.