I am using bitsharesblocks median feeds on cryptosmith.info ...
BTS median price: 124.20 BTS/bitUSD
bitSilver median price: 2,003.83 BTS/bitSILVER
2,003.83 / 124.20 = $16.13
Price of real silver: $16.88
Difference = $0.75
its slowly catching up but its been off for 10-15 mins.