First of all it's not an ego thing. Yes, like you, I do like money, but I originally had no plan to increase the price for the e-book. However, as the novel grew in length, so did the amount of time and energy and cost of publishing it. I use editors, both free and paid, to put out the best possible book I can. So a longer book means more cost.
Normally, I've charged 4.99 for ebooks. For Alpha I'm charging 5.99. I feel like it's fair to ask 6 dollars for a few hours of solid entertainment, especially since this book is significantly longer than previous books. Like 40K words longer. If Omega, the last book in the series, is shorter, I'll revert back to the 4.99 cost.
Paperback costs are determined by Createspace, the print-on-demand publisher which I use to make my paperback books available. I can't do much about the cost there. I wish I could make it lower, but I try to retain a healthy profit while the publisher takes the vast majority of the sales price. Hopefully the cost won't be too outrageous. I won't know for sure what that is for a few more days, when I load up the final file and save it to their servers.
So, thanks for being understanding fans. I hope you won't begrudge me the extra dollar or dollars, but they help offset the increasing costs of a longer book, which you, the reader, get to enjoy. Only 3 more weeks until the book is yours! Happy waiting.