After some research I have found that limiting your offer on the sales page incredibly reduces refunds, allow me to elaborate.
Lately I have been receiving a lot of e-mails in regards to a specific information product that go like this (paraphrasing):
"I purchased your product expecting a good deal, but I didn't expect more than that and when I went through the whole package I was shocked to see I got much more than what I payed for. I really didn't think it could get any better, but it did."
I actually stumbled upon this "trick" by accident, but it works.
In my sales letter and other places where I pitch the offer, I do it in such a way that it is a great offer, but I don't mention it all, I even "forget" to mention certain bonuses included within the package.
This way, the perceived value of my product pre-purchase is high, but it is not as high as it is post-purchase.
It also helps so that the potential customer is not overwhelmed by 1,000 bonuses and makes the offer a lot more simple to absorb.
I say I stumbled upon this by accident, because in the copy of the product I really forgot to mention some of the bonuses, so when they bought it and saw the package, they were looking at more than what I offered.
I am certain this is one of the reasons for such a low refund rate (I've done the testing and research), so I hope this helps.