i made mine back in december-
2x$40 for 4foot lengths of stainless on ebay
1x$30, the air ram was from a truck supplies shop-
Queensland Diesel Supplies
the rubber bends were from Harvey Hose - now Purple Pig
3x$25 each (2x45, 1x90degree's)
7x$5hose clamps were from harvey hose
1x$10 tube of Neutral cure Silicone (doesn't rust bare metal)
$10 of nuts, bolts, washers and spring washers
some aluminium i had lieing around was used for the A-pillar bracket
drilled straight into the side of the air box and blocked the other side off with some 8mm industrial plastic (40L turps container cut up)
total cost was just over $200
you might want to consider plugging the drain hole in your air box (but if some prick pours water down your snorkel, and you crank the engine, the engine is toast)- bit of a trade-off, or you could just make a wedge to plug into it when going offroading, but unplug it afterwards
the improvement in induction was instantly noticable, easier rpm's on the highway, more throttle response, instant improvement on economy