Kristin B,
Denver is a huge city so it depends somewhat on the parts of Denver and the parts of Arvada that you'd like to compare. I would say that they are very similar. Arvada has an eclectic mix of low affordable homes, middle class and luxury homes. There's something for everyone here. As for prices on food, gas, etc. there is no difference.
I'd say one of the big differences between Arvada and most parts of Denver is that there just doesn't seem to be the congestion on the streets of Arvada that you would see in most Denver neighborhoods. You can get to pretty much everything you need within 5 to 15 minutes.
Check us out. We'd love to have you as a resident.
