Good on you, Emma
Opshopping is a great way to build up a stash cheaply.. I've had some great scores, including fleece covers, random fitted wahm nappies, those fluffies brand cheap fitteds that work great at home during the day on my newborn, brand new in the packet flannelette squares, tons of old style eenee covers, good quality terry squares that people have obviously never put on their child's bottom... even a few PUL covers

If you can sew, bumjumers made from opshop jumpers are awesome