You have to swallow your pride and take a really honest assessment about how the quality of your stuff stacks up against others'. Are the models in your videos crazy hot? Or are they a little older or overweight? (Some like that, but generally it's a negative.) How rare is the content you're selling? If you're doing full-on wam sex, that's rare, as is a scene with a bunch of models, or a well-done wedding dress wam scene (wink, Midniter). Also take into account the resolution, lighting, and general quality of your work (though this matters a LOT LESS than how hot your model is and how she's wammed). Also how you package the content may make it more valuable: Are you bundling multiple formats or resolutions, or giving a pic set away with it, or offering a bundle of various scenes or pic sets together?
Take a look at the UMD download store and sort by Most Sold. The best-sold scene was of a really cute girl and bundled a bunch of files, and sold for 7.99. The second-best-sold scene was rare explicit sex in mud, and sold for $21.99. Rarity and model quality do make a difference. With that in mind, take an honest look at where your stuff stands in the wam world, and see what others who make similar stuff are charging.
Stay messy, my friends.