So what's your #1 concern, is it the need for more variety or is it having a limited budget? If it's the latter, may I suggest dumpster-diving (serious). Gotta love hunting-gathering! I got some parsnips, carrots, bok choy, celery, and a ton of fancy herbs (all organic) just last night. All you need is a flashlight, a stick, and 0 self-consciousness.
Also, another cheap option, especially this time of year, would be all sorts of squash/pumpkin and root vegetables (parsnips, beets, rutabagas).