Is it worth roasting my own red peppers?
I roast them "fresh" as I need them, but my method scales up easily.

I use a gas grill and turn it to high.   Set the whole peppers on the grill, and turn them when the skin is black on the hot side.   When they're black all over (after maybe 2-3 minutes per side for all 4 sides of the typical ones in my local supermarket), I put them into a large disposable plastic container with a tight fitting lid and let them cool in it.   The skin peels off quite easily, and they can be seeded and de-stemmed quite easily.

If I were going to preserve them, I'd probably chuck them into a plastic container or zip-top bag and freeze them.