I have no idea ...
I'd guess it's at least a week of full-time work ..

I wish I could code , could you estimate how much would it cost to get someone work on it ? Ball park figure...

the referral program is to capture startups and business .. not customers ..
But I agree that the stealth feature should be considered important ..
Now, the issue is .. who can work on it? Anyone up? It's essentially just javascript/coffee script coding ..

I am just emphasizing  how important this is to attract more people to bitshares. I hope its possible to include this in the gui .