I've finally gotten to where I could purchase the prototype for this board. A whole new estimate was needed; the total I spent was $262, including $5 for an unrelated test board and a $12 bank processing fee. If I get any more, I may see about using a company other then PCBWay; they're wonderful (especially the customer service reps), but the price seems awfully high.
I'm figuring it'll be mid-June before the board arrives. I'd better start getting the other components ready for testing!