I currently have a bit over 90b isk ... i am not in a hurry to sell it, so i will not sell for underprice to ruin the trading rate. However, if you buy in fairly big bulks, i might make some discounts for you.
Prices are 1600-1700 fg each billion, depending on the quantity you are buying, and your negociation skills. Maybe even less if you buy a huge pack
plexes are 875-935 fg, depends on how many you are buying (math made at 550m isk/plex). Quantity available : over 160 plexes
last topic where i have traded 35b isk, in some cases i received first and everything went smooth during / after the trade too
http://forums.d2jsp.org/topic.php?t=65918339&f=84