Best place to SELL silk?

[Grad]

i seem to get lucky destroying lots of pirate frigates and in he cache 6/10 i get bolts of spidersilk or parabola. I have 13 in my inventory but don't want to sell unless i can get best price. It would be a different story if i only had 1 or 2 pieces. Should i go to the surface and sell or is there a better place?

[Wlerin]

Can't sell it on the surface, afaik. London buys it for 50 echoes. I don't recall if there's anywhere better.