To be honest at the moment nothing sells really much, but there are a few things that people are more interested in. First of all I'm guessing you know that you must forget about all the SS08 things wether they are backgrounds or trinkets they barely sell at all on here.
You can easily trade for the 'three' wigs ; Isca, GMC and Court Dancers which would put you to around 160-170 caps.
There's also Butterfly Dress which would add to make it 220.
PMC background is also very popular and would make it 260.
For the remaining 140 caps or so I think your best shot is mid-end NC items.
Things like Cherry Blossom Garland (16-20), Golden Outdoor (10), Wish on a Star (10), Healing Springs Foreground (12), Clouds of Ghostly Orb (15-17), Zencos (13-15), Nutcracker FP (15), Darkness Attacks (10+), Bakery Display Case (10+) and the Three NY BGs (30+).
There is also the other possibilty of trading the 140 caps remaining for GBCs, if you find someone interested. You can discount to 100 GBCs and sell them for $1.25-1.50 each.