Oprah did a show recently about the cost of fresh foods vs. fast food - very eye opening. But, the moral of the story was that even if they're expensive, it's really important to get them because of the nutritional value vs. preservatives, extra fat/sugar/sodium in pre-prepared foods.
I'm personally against hiding them in other foods - it doesn't teach your child to learn to like the flavors.
Maybe I'm lucky because my kids love veggies - particularly love frozen mixed vegetables. I've found the Birdseye brand to be better quality than the store brands, and it's usually on sale at places like WalMart.
Edamame is another great source of nutrients. You can buy shelled Edamame at most stores. My kids will eat lima beans but prefer edamame if given the choice.
We do a lot of green/red peppers. Green is usually less expensive, but you can sometimes find good deals on the other colors. Costco/Sams Club carry miniature sweet peppers that our kids love, too. They also have sugar snap peas (fresh) year round.
Cauliflower can be tasteless, but if you prepare it by lightly sautee-ing it and adding some parmessan/romano cheese, it can really bring out the flavor.
Fresh green beans are great.
Potatoes are not really vegetables (though relatively good for you, they are a starch and thus a source of carbs).
You can also get Broccoli slaw to add to salads or eat by itself. It's thinly chopped, so it should be fine for a 22 month old to eat with supervision.
Good luck. I hope this helps.