Elegant clothing is super cheap depending on the color you buy for female sets:
http://runescape.wikia.com/wiki/Elegant_clothing
Vestment Robes don't look too bad either but you'll need 20 prayer. The capes are much more expensive I believe.
Then there's always G\T\H1-5 armor.
For hats you can look at the top hat, animal masks\dragon animal masks, boaters, berets, cavaliers,
for weapons, canes, which come in rune, black, and addy. God books are nice for the shield too.