[FONT="Century Gothic"][SIZE="4"]I'm really liking your idea of using four DPNs instead of five. I think the result might be dependent on the types of stitches used in the pattern and how the pattern is written.
For example, if directions are given to do X on "Needle 2, 3, etc." then you'll just have to be extra careful that you're paying attention to which needle those stitches are on now that you have less needles than the pattern asks for.
I hear you on the large chain craft store. I don't know where you live... we have a large chain as well, but I've been trying to go to our local craft store here in town (old fashioned mom & pop going out of business), and they have a ton of stuff that JoAnn's doesn't have (funny, they don't have yarn, but they've got needles!). You might not be so lucky.
If you have a Michael's you're bound to have a WalMart... our WalMart carries aluminum DPN (I personally like wood, but...) in smaller sizes.[/SIZE][/FONT]