A lot of dark chocolate is "accidentally" vegan. Sounds like you're in the UK so check out Scottish youtuber NaturallyStefanie - she has loads of videos called Accidentally vegan with sweets, chocolates, biscuits etc. from main brands that you can find in Tescos, that all happen to be vegan. I very seldom pay extra for chocolate that is marketed as vegan, but instead just buy dark chocolate in the grocery store and check the ingredients first to make sure they are vegan.
As for vegan cheese I have one kind I do like, and it is expensive, but I only have it once a month or so. I decided when I changed my lifestyle to a vegan one that I would just skip stuff like that (most of the time), not only because of the cost but also because it's all empty calories. There is so much out there that is natural, vegan and actually full of nutrients... so I prefer that over pretend cheese. It's just a habit to have cheese on things.