I had never played any games in the Advanced Wars series before, but I definately got my money's worth.
I had seen my friends play Advanced Wars games on the GBA before, but I never put a thought into if i might like it, or if it was worth buying. I found out it was coming out for the DS so i figured, "hey i could use a strategy game to relieve my boredom." A few weeks later, it came out, and i purchased it. I got home and got right into it, seeing as i had nothing better to do. Turning my DS off some time later, I realized I had played well through the day and it was far past the time I should be going to bed at. Advanced Wars DS is highly addicting.
If anyones unsure of whether this is a decent buy or not, I'll re-assure you its more than worth your money. I'd have paid alot more for this game than what its worth just because of how fun it is.