Wannabee,
We started out at $8.90 but quickly determined that wasn't going to roll for a debut novel, no matter how well written. Almost everyone was doing $2.99 for theirs but we noticed that most were 60~80,000 words, where's "Tree of Life" is 120,000 words, so we decided that $3.99 would be a fair price for that amount of work. Fortunately the reviews that have been coming back essentially confirm that the book is worth the price.
We're self-published using Lightning source for the dead-tree version and the eBook we host/sell ourselves but additionally we have it listed on Amazon and Goodreads to capture additional potential markets/exposure. We could also try Smashwords but we're getting a bit concerned about the excessive spreading, especially when you consider that each location usually has a minimum accrued income before they payout, which means you could end up with $200 of sales spread all around but still not have a single payment
Paul