what brand of strings are for your guitar?

If you really loved the sound of your guitar when you bought it you could start by finding out what kind of strings were on it to start with. Just remember that if you don't change them often your base strings will loose that full sound that accoustic guitars are known for. You may find that with new strings it doesn't sound the same to your ear.
I recently changed from Godin to Gibson strings. I find the Gibsons' have a crisper sound. It is trial and error, personal preferance, finger strength..etc.
As for price well that depends on your budget. If you find that you can't afford what you like then there is always birthdays and Christmas. Ask for Strings! I would be happy to recieve a half dozen sets. Or put a little aside each day/week and don't touch it. The difference between a midrange string and something a little more expensive is usually only 5 to 10 dollars. In my case I was supprised that the gibson strings were a little cheaper then what I was used to paying.