$5 for either a set of Ernie ball Slinkies or a set of DR's.
I buy as many sets as i can of discontinued strings for $2 a pack for weird things i make and want to test out- then, after they're ready to go, i put a $5 set on them.
I'm not one to change strings after every gig, so it works out just fine.
I recently bought some GHS Boomers at my local shop for $3.86/pack. The E Balls were $4.29 as were D'Addarios. I decided to try Gibson's Brite Wires on my LP for $5.99 (imho, they ain't worth it, I'll go back to the Vintage Nickel Gibby strings..but they are $6.99 a set now !).
My last purchase was a 10-pack of D'Addarios for $3.32/pack and it came with a 3-pack of Planet Waves 6" cables and free shipping (because I tossed in a set of Everly Rockers)!
I buy Ernie Ball at GC for around $4 a pack
I can get them at a local store for $10, buy one get one free (like that's a deal or something). It's closer.
There's another local store that charges $8 for the first pack, second pack is $5. I don't buy them there anymore.
How do you get em to do that? Bring in a print out of a cheaper price on strings and they'll match it?? Sounds like a good idea if so, the shipping on strings can be kinda ridiculous unless you get a lot of sets.
I pay $8 for Gibson BB King Strings. They are pure nickell and they last a really long time. I like old strings and these one stay good for up to a year on my guitars.