Quoting crazy coupon lady:" I would cut out the toddler formula (which is needed in kids with low weight) I didnt read all the replies ... [snip!] ... some cauliflower in the cheese sauce they wil never know the difference. It will be so much cheaper then that formula."
I agree with this. It's just going to take a little bit of work/trial and error before you find out what foods your toddler will or will not eat. If you're going out and buying formula, there's no reason to not go out and buy healthy snacks/meals. Granola bars (make sure there aren't any huge nuts in it), peanut butter (i recommend smart balance), bananas, apples with no skin - cored and sliced up, yogurt. Cheerios (not the sweetened sugar coated kind), vegis with dip. Hummus and pretzels to dunk. Apple sauce - no sugar added, triscuts, reduced fat cheese sticks are ok, cut up turkey lunch meat, whole wheat english muffins,etc
Toddlers normally eat very small portions compared to babies, especially at 2+. I'd start off with very small portions. That way you don't throw away anything they don't eat. There will be meals where you'll be lucky if they eat a mouthful or 2 of food. It's part of the fun of toddlers.
There are a few medical reasons why kids should be on formula past 1ish, but normal healthy toddlers should eat a balanced diet of 3 meals a day with a few snacks inbetween. My 15 month old normally drinks about 3 sippy cups full of some type of liquid, normally whole milk or water.