I have made 3 fursuits before, and Ive done all 3 off of one bag of foam cut offs from para rubber, they are only $5 for the whole bag! its honestly the best and cheapest way to go for foam. Also, yea, spotlight is the top dog for fur, although, good furs are expensive :S I once bought 1/2m for $50, but it was worth it :3
Yes, bags of foam offcuts from places like Para Rubber are great for fursuit work. Also searching your local craft and variety stores for offcuts and end of roll pieces of fur is worthwhile too.
Spotlight is probably the most reliable place to get fake fur, though they are on the expensive side. Bulk suppliers like Furtex in Auckland are cheaper, but they have a 5m minimum cut, unless you find an end of roll piece, which is a lot more than you need for most fursuits. There are also online suppliers, which are the best place to look if you need a specific colour or pattern, but again, minumum order sizes and shipping can make them rather expensive to deal with.