If the product you are selling is really good, and as far as I'm concerned you have targeted a good market, you shouldn't have any problems at all.
Honest people do not ask for a refund on a product that they feel delivered what was promised.
Most people are honest.
You really don't want any charge backs at all, so you should offer a liberal money back guarantee, and immediately give a refund when asked. I give my customers one full year to look my stuff over.
If you are getting a lot of refund requests, then something is wrong. Either your product is inferior, or your marketing is inflating the product too much.
I can tell you right now that if you really offer a good product, I would venture to say that the market you are targeting will request very few refunds.
I would have to say that people that would even consider paying for such a product would be in a high enough income category that they will only ask for a refund if they don't like the product.
If they really, really like the product they will throw money at you like crazy!
Then again, only testing will tell for sure.
"The Dumb Ole Dirt Farmer"
"Free-"37 Secret Money Making Strategies"