You don't want 10w30, you just want 30 weight oil. multiviscosity oil would be worse than pointless on a bike chain. You want the 30w. 10w30 will act like 10w when cold, which it always will be.

A quart of cheap 30w oil is about $1.50, and will keep even my chain lubed for years (at an average of lubing it once a week).