freezing cakes

Fine to freeze most cakes, especially sponge ones but not choux pastry. I can tell the difference but as most of the people buying them probably never make their own I don't think it will matter a bit. Please make sure they are priced properly, so often the cake stall sells out very quickly but that is because they have been sold at below what it cost to make them.

Jam buns and rock cakes are cheap to make and sell well.

Margarine works well and no one will notice. Freezing will not spoil them.

Margarine works, but butter is nicer. Whatever you do, don't use light spreading margarine (unless specified in the recipe) which won't work.

Butter makes a huge difference to the taste, as do good eggs.

I agree, AlisonMA It is very easy to underprice home baking. If it is for a charity, there is a temptation to assume "It was donated, so anything we make at all is profit"

You should calculate the price of your ingredients, including all the things you used "only a spoonful" of, and add in the cost of power for cooking.

Then cost your time, at the minimum wage, at least. It is all very altruistic to think "But I did it out of love, my time does not count" - if your time is not converted into cash, you have not really given it to the charity.

(And you could add a bit more on top of that for the profit you would have to make if you were doing it as a business - a professional has to make a working surplus as well as cover their own salary.)

Don't worry about anyone comparing the price with what they would pay in the supermarket, They are getting a product made up to a standard, not down to a budget.

And you can always reduce the price later on but you can't put it up once they are sold!