The chicken last time was fine. If I had been doing the challenge for more than a week, I probably would have bought a different kind of meat the next week, just for variety. Meat is an expensive item, and I've found I need to limit myself to about a pound a week to make the budget work. The rest of the protein comes from other cheaper foods. I did manage to have coffee both times, though!
For the vegetables, I bought what was cheapest, as long as it would fit in my planned menu. For example, last time I bought cucumbers (which were a steal at 5 for $1), but this time they were 2 or 3 for $1, so I opted for other things. Onions were more expensive than last time, but still affordable (and they're very versatile). Carrots (the ordinary kind, not baby carrots) are also usually very affordable, and celery happened to be on sale also. Navel oranges were cheap, too, though a lot of fruit is higher than last time. I happened to hit a big sale on broccoli and cauliflower, and stocked up. My local supermarket also had frozen veggies on sale, which is how I was able to afford the peppers and stir-fry mix.
I should point out, for anyone reading this, that even if I were paying full price for everything, and never getting the benefit of sales, coupons, or freebies, my budget would still be pretty low. Probably under $50 for the week. The foods I ate are not terribly expensive, and anyone in the US (or most of the US, anyway) can do this.
Here's a link to my earlier budget challenge journal, in case anyone is interested:viewtopic.php?f=7&t=97061&st=0&sk=t&sd=a