I think the slight backlash at the member suggesting peelings was pretty harsh if I'm honest. Yes it is very bad if you're giving potato peeling, but the member did not specify what they are giving. There is absolutely nothing wrong with giving piggies the odd few carrot peeling (only in moderation), I also give mine the offcuts of celery (chopped small), cucumber, broccoli, beetroot etc which is perfectly fine and healthy.
Just a note on buying pellets in bulk, the vitamin content is only guaranteed for a certain amount of time from manufacture (3 months if I remember correctly but may be different), so don't buy more than you are going to use in that time period - bulk isn't always better.