Hum! If I were stranded in the South Seas, and assuming a PLB wouldn't be available, I think I'd like to have the following:
*2 poly tarps (mostly for water collection, but also shelter if trees/brush are scarce) $9.98
*wool blanket $28.99
*5 gallon plastic jerry can with a bit of fresh water already in it for starters $16.99
*Datrex survival food bars (3) $15.00
*portable fish net trap $24.75
*knife $29.99
*camp hatchet $15.41 (or alternatively a machete -- depends on terrain)
*first aid kit $42.75
*small signal gun + flares $60.99
*flint steel $7.63
*pack of Bic lighters (20) $19.99
*100 ft paracord $11.99
*pack shovel 2.49
*mosquito net $12.99
Total: $299.94 (before tax)
--M