I'd have to agree with the above comments.
I think you have it priced pretty fair, especially with the subwoofer upgrade and the condition looks great in the pics. A few crisper ones with the glass off may help. People want to see a perfect looking play field.
I think it's a little slow right now for the used game market, which surprises me with tax return season in full swing. I have had a few games listed for a few weeks all just below the estimated value on Pinside and had plenty of tire kickers but nobody super serious. Sold a LW3 about 2 weeks ago. I'm in between a few major cities though so it helps my reach. And I have ads up in multiple places online, so that helps me get more exposure.
I wouldn't go much lower on it either, you don't want to give it away. It's priced fair. It's a game I have in my collection and I'd have a hard time even thinking about selling it. It's a Williams, wide body and made during some of their best years. You can't go wrong with the combos, it's a fairly easy ruleset but still challenging and all the different multi balls are all awesome. Incredibly durable and reliable as well. Good luck!