The cost of a belief

I think it is safe to say that as a student life can be difficult at the best of times. Many are living away from home for the first time, struggling to balance incoming money with out goings.
Much to my dissapproval the nearest supermarket to my university is a Waitrose. I love the idea of Waitrose, a company whose workers get a share in the profit. What I do not like is that it is making life for me expensive.
There is a sainsbury's nearby which will sell the products that waitrose sell or something very similar. They do, but why do vegetarian alternatives have to be so expensive. What I don't understand is how something that is produced from beans and seeds and things that are VERY cheap to come across can cost so much. Is that reasonable? £3 for a small tray of chicken style strips when you can buy the actual meat one for half that?
Somewhere, being a vegetarian became an expensive business. Even vegetables don't seem to be worth the money you're paying, £2.59 for a small bag? It would take a fraction of that to both grow and harvest them.
I love being a vegetarian, I feel a lot healthier. I eat more fruit and I am less depressed about consuming something that once lived. What I do hate is having to fork out a stupid amount of money to continue a belief.
If anyone knows why it is so expensive to buy Quorn type products let me know, personally I feel like I am being robbed by corporations who should know better.