I understand the desire to have many many horsey babies…lol… I’m on the search myself…
I’ll give you an objective answer… I really like your mare, and she is bred pretty well; however, in terms of pedigree, I don’t think these two horses match the best based on one horse: Northern Dancer. If it was another stallion, I might have another opinion. I support line-breeding as much as any other pedigree analyst, but ND is where I draw the line. I think the reason that American thoroughbreds haven’t been getting better and better, and the Europeans are consistently outclassing us is because of our obsession with stallions and ignorance of mares, Northern Dancer, Dirt and our unwillingness to breed much else except that which sells in the auction ring. ( 3 of those topics I’ll publish a book on later instead of boring you here… 
)
Here’s what I see… Your mare is already line-bred to Northern Dancer, as well as horses related to him (besides their occurances in his pedigree): Nearctic, his sire, Nearco, his grand-sire and Native Dancer, his BMS… And so is Regal Sanction… So, the foal would be line-bred to Northern Dancer. He’d appear 3 times in the 4th generation, and do you have any idea how many times Native Dancer would appear in the foals pedigree? Minimum of six times… Yes, there is a nick that suggests that a Northern Dancer/ Native Dancer cross can add speed and stamina, but personally, I think your mare and the stallion are already line bred that way. The costs will more than likely outweigh the benefits. Take Charge Lady is the way many pedigree people think that nick should look, Northern Dancer through Vice Regent and Native Dancer through Mr. Prospector. (however, I think the Secretariat influence in the sire line [i.e. Storm Cat, A.P. Indy & Gone West to name a few…:-D], and the Rubiano/Blushing Groom cross is really what made that mare so successful!)
For breeding your mare for TB racing, I would suggest an outcross away from Northern Dancer, but add stamina or endurance (Rubiano was a sprint champion). Stallions by Blushing Groom or even Seattle Slew would probably be the best, since your mare is by Rubiano. There are several successful sprinters bred Rubiano/Blushing Groom. Wild Risk and Fappiano seem to work well together when the Fappiano/In Reality cross is already present or diluted. The argentine stallion, Forli, would be another interesting family to contemplate as would lines including the stallion Halo. ( The stallion Rahy is actually a perfect example who also crosses well with Northern Dancer influenced families, but his fee $80k)
If you do decide against this novel of better judgement that you want the Northern Dancer X, here’s a better idea than Regal Sanction. If you’re in New Jersey I would take advantage of Defrere. He’s a full brother to Dehere, leading NJ sire for 3 years, and is $75k less than Rahy…
) He also seems to produce decent earners out of sprint sired mares…
It’s kinda like New Yorker’s and Freud… He’s a full brother to leading juvenile sire Giant’s Causeway, and he’s in New York State!
So! There is some food for thought… I’m pedigree crazy, and outspoken… but hopefully you still all love me… Also, in TBs I feel like cheap stud fees is something to be very wary of… If you want an awesome horse for $1500, find a warmblood stallion. The foal will also have a much higher value when it’s born, since foals from sires w/ low fees (at best) triple the fee.
-Kerry
P.S. SO jealous that you Aussies have access to Dehere…
