For under $300 you can buy lots of top end boards for cheap.Don't buy anything that retails for under $300 and don't buy anything unless it 50% off retail.
Especially when it is wide and long sizes.
You just have to do your research.
Boards I have bought for friends at 300$ and under (current yr or prev yr when bought):
3 new Burton fish 156 for $275,$290,$300 (one of these I outbid spencer on)
3 GNU DK Monster 155 for $230, $250, $275
1 GNU Billy Goat 159 $265
1 k2 WWW 154 $180
1 Never Summer EVO $250
1 Rome Notch 155 $265 ( should have got this lower)
Also try Buy/Sell Used Outdoor Camping and Hiking Equipment at GearTrade.com - #1 in Outdoor Gear Exchange
and look for seller "Backcountry" for good deals