You could find the 256GB Samsung 470 OEM version on eBay for $300 easily. It has the same architecture (read:speed) but it doesn't come with the 3 year warranty or the nice aluminum casing. It does weigh 2oz less. That's the best bang for your buck.
Although this is against eBay's rules (screw them), you could message the seller, offering to pay $290 or so through Paypal so that there are no seller fees.
Also check out the Kingston V+100 on Newegg and Buy.com, they go on sale for great prices very often.