Silk scraps used to sell for one copper more than their vendor value. I told everyone to buy them (along with thick leather sections) because they were a high end tier item that ArenaNet would focus on "fixing" in the near future. Then they shot up to 2 silver in less than a month's time.
This all occurred prior to the Escape from Lion's Arch event, which had a huge influx of silk scraps thanks to salvaging the various high level items you get from LA. A single game could easily net you 30 silk scraps, and you're encouraged to play it many times over. So this has led to a dip in the price of silk scraps; specifically to 1 silver each.
I've been telling members of the forum to buy silk scraps for weeks now (as low as 1 silver each), and just recently they started their slow return to the 2 silver mark. If you can grab silk scraps for under 1 silver 50 copper then you know that you'll be able to make 10 copper selling back at the 2 silver mark.
If you get silk scraps from salvaging then please please please do not sell them just yet. Hang on to silk scraps for a much bigger pay off at a later date. Keep in mind that they may dip again throughout the event, but rest assured that afterwards they will rise again.