Color me silly, but I have always just used the internal osc. Never had any issues yet. And for $5, if you use 1 or 2 of them you could feel good about the purchase. then build some tree decorations with the rest. That way the $5 purchase won't continue to cost in design, board space, pins, and headache.

just my $.02

I am sure I will invoke lots of replys citing the accuracy of the internal osc. Bring them on. IMHO there are but a handful of applacitations that require greater than the internal will provide.