I spend $200 per week on food for 2 adults and 3 kids (9.8.6). Ways to spend less: don't worry about specials and cheapest things - simply avoid junk food, pre-packaged food.
Instead of instant oatmeal or cereal or bfast bars, buy bulk oats or make eggs and toast.
Instead of individual cheese sticks, buy cheese and cut it in to chunks. Grate your own cheese.
Instead of frozen pizza or take out, buy fresh pizza dough in your refrig section, pour on some pasta sauce and grate your own cheese.
Instead of bagged prepared salad, buy a head of lettuce.
Instead of chicken nuggets, roast a chicken (email me offline if you want help in that - 350 degrees, 20 minutes per pounds plus 30 minutes). That will give you dinner for three nights: one night roasted chicken, one night chicken enchiladas or casserole with leftover chicken, and another night of chicken noodle soup made from boiling the leftover carcass.
For the toddler, just puree or chop up (not sure age of toddler) whatever you have for dinner. He'll get used to it - just don't give him something he likes better if he refuses what you give him first.
Hope this helps.