Hello, I can develop a C# api library that get bitcoin prices from different sources like Bitstamp, BTC-E, LocalBitcoins and offer different types of value, real time Price per source, average real time Price, average Price depending on the source and volume of transactions, etc.
I myself have Bitcoins, so I know how does it work and I have already done a Little code to get the Price in real-time. If you have any question or specific requirements please let me know. I can send you a Little demo if you want to corroborate my knowledge and see my work.
Salvador.