1) You need to radically increase the professionalism of that website to support the $499 price point. That price point is not necessarily high for someone in an IT group at a large company, but he cannot pay it to
you because everything about your site -- the design, the copy, the video, etc -- screams "risk."
Look at other sites which successfully sell to large corporations with buckets of money and try to hit the note of restrained professionalism they go for:
http://www.fogbugz.com
https://spideroak.com
http://smartbear.com
I picked companies which are on the smaller side. Importantly, they don't look like they're not Real Respectable Software Companies of the sort that will cost you your job if using their software breaks your entire office for a day.
2) Price is typically not the reason software fails to sell. What is your strategy for acquiring the attention of people who have $499 to spend on software deployment? If I were you, I'd be thinking along the lines of creating lots of content specific to their needs, since the organic SEO benefits from doing so are substantial.
At least one B2B business hanging around the forums has had success with this -- they turned a source of data that they already had into a lot of pages, and those pages have lead to leads which bought things priced substantially north of $500. Hopefully they will chime in with their experiences.
3) You need radically more textual content, to answer the numerous worries your prospects have prior to shelling out $500 to you.
4) After someone credible buys this software, get approval to use their logo and then mention that it is in use at Respectable Brand Name. This is social proof and decreases the perceived risk of using your software.
5) (Much love to the HN community but I have to say this.) Ignore the opinions of anyone who says "Reduce the price" that does not also have authority to install this software at their corporation, because they are not your customers and they will not buy your software at any price. Among many other reasons: price signals quality, and if you adopt App Store pricing (or even $29.95 pricing) you will be communicating that you are not nearly reliable enough to be trusted with computer systems which would burn six figures or more a day in the event of downtime caused by a botched deployment.