Replacing Butter With Margarine

Butter is expensive and we tend to use a lot of it so I have been trying to think of ways to cut back.  We use it in a lot of dishes so it would be next to impossible to cut out.  I hate the thought of using margarine but the container said "cholesterol & trans fat free."  Its only for a year.  Will it kill us?  After researching it online, I don't think it will.  I still prefer natural foods over man-made so we'll get back to butter as soon as we can.  : )

Here is what the Mayo Clinic has to say about it.

1 lb of butter from Aldi is $2.29
2.6 lbs of margarine from Aldi is $1.79

We are going through 1-2 lbs of butter a week in things like mac & cheese, grilled cheese sandwhiches, toast, mashed potatoes, etc.  I think 2 tubs of margarine will last us the entire month.  We shall see.