Roasting veggies is a pretty good way to get people who think they hate veg into eating them. As you roast the veg, you bring out the natural sugars in them and deepen the flavours, as well as give them interesting texture. My husband used to hate pretty much all veg that wasn't peas or carrots, and with a steady introduction of roasted broccoli with lemon and parmesan, roasted carrots with curry spices, roasted brussel sprouts with lemon and thyme, and roasted cabbage with dill seed and olive oil, he opened right up to eating veg and is now on the semi-vegetarian track with me. It's just a matter of looking for different ways to eat veg and introducing them as a thing with flavour and interest on their own, not just a mush on the side you have to eat.
Also, soups are a great way to get veg into things. You can build a lot of flavour in soups and the veg are a part of it, they don't just stand out on their own. If you've got an immersion blender, it's really easy to make pureed, velvety soups where everything blends instead of facing down a bowl of veggie chunks that might turn him off. Mileage may vary, though -- my husband loathes pureed soups, so it's not a sure thing.
I'd talk with him about your eating habits and your need to budget better, and work with him on introducing things into his diet rather than springing new food on him. People who are active participants in picking their own food tend to accept change better. Otherwise, it's easy to get pushed into the corner of being the mom-like figure who's making him eat his veggies. Involve him in the process. Push him to find things he's willing to try. Look for recipes together. Agree to try a new thing every week or every two weeks. And while you're in that process, keep adding veg to things he already likes -- add it to pasta sauce, work minced carrots or mushrooms into hamburgers, etc. But he's got to be on board with the change, or else it could turn into you buying and cooking food he refuses to eat and him going out to spend money on takeaway. So try to work together.