I got an email that said some of the Vera Bradley prints were on sale (half off). Not sure what colors/prints you like, but I'd check the website if you were interested in one.
This. I just got the large duffel in a discontinued print for $42 (regularly almost $90!). Check their web site.
My sister had a Vera diaper backpack and LOVED it. I got the Petunia Picklebottom boxy backpack, which is quite expensive as well, but I feel like a diaper bag needs to have some quality to it, as it will be my primary bag for awhile. Those things take some wear and tear over time! It might be cheaper to get a more quality bag in the long run, rather than having to buy a few cheaper ones.
ETA: I've also heard advice from several friends and family members to get a bag with a backpack option. It frees your hands. Carrying a heavy bag on my shoulder while trying to work with a stroller, infant, etc sounds cumbersome .I have small shoulders, so my bags tend to slip down.