calculating ads at 850k (but you can probably sell for 900 to desperate ppl)
Doppel Ganger Card - only slightly cheaper in the item shop than ig. (20m in shop v 21-22m ig)
Turtle General Card - same
-recommended you sell ads and buy a completely carded weapon ig because they're usually cheaper by about 10m
Celeb Ring x2 - sell ads, buy ig (46m in shop v 42-45m ig)
Kahos Custom x1 - most definitely sell ads and buy ig, doesn't matter which you can always put out 5ads to change the customization (100m in shop v 83-90m ig). you'd need to add about 70m to trade for a valk[1].
Pussy Cat Bell Custom x1 - sell ads, buy ig (idk how much custom bells are ig, heh. but as the pattern shows, it's probably cheaper ig.)
Dark Lord Card x1 - same as dopp and turtle, if you want sleips, you might as well sell ads to buy DL sleips. ignore the vendor selling at 100m right now >> DL valks are cheaper in shop (48m in shop v 55-57m ig) and if you're just after regular +7 DL shoes, it's best to buy ig, i see those running for 19m sometimes.
Gryphon Card x2 - usually cheaper in shop (13m), if you want a valk helm, you might as well sell ads to get a gryph valk. for mid head gear to put this in, it's cheaper to buy ig. if you see a gryph mid you like at 20m-21m ig, buy it.
pc.bot.nu is your friend.

careful of scams. =3 make them pay you before you transfer ads.