Windage trays cost a lot less than $300, mine was about $70. They do a couple of things, all for the greater goal of keeping
oil off the crank and down by the
oil pump pickup where it belongs. The diamond screen type are the good ones, those with punched baffles are OK. They act as a crank scraper to some extent, scraping the blobs of
oil off the crank and rods as they pass by. (Often use an actual crank scraper too, custom fitted and ground) the windage tray also prevents oil from sloshing up during cornering braking and accellerating. They are good for a little hp gain, just by keeping oil off the crank. You have to have a pan which will accomodate the extra long main bolts and windage tray, and careful fittment is required so the crank and rods don't actually touch the tray.