After doing some (very brief) research, the average price point for you product is between $130 and $150. Your discounted price is at the top end of this scale. Also, the fact that so many of your sales come from your discounted rate suggests that your regular rate needs to be (urgently) revised.
Also, have you ever tried providing monthly, quarterly or 6-monthly access to your product instead of a lifetime access?
There should be no need to hold a sale. In the long to medium term, reducing prices has never been the answer. By this stage you should've already worked out where you are in the market and what your optimum price point is.
You should focus on providing the very best service possible and work out, from your customers' perspective, how you can add value to your product.
Once you've done this you'll be surprised at how less important a factor the price become to new customers. Also, these new customers will stay with you longer as they aren't fickle about price and so won't jump ship as soon as something a few pennies cheaper comes along.
This sounds like a very interesting project. I'll have to admit, I'm intrigued...
I come from a very strong sales and business development background and have currently left the 9-5 grind to pursue freelance work that allows me to manage my own time.
Aaaanyway... I'd be more than happy to have a chat with you and see if, together, we can come up with a game plan for you.
Also, have you ever tried providing monthly, quarterly or 6-monthly access to your product instead of a lifetime access?