We went in to the craft store armed with our list of supplies but found that on a budget, craft stores really aren't that friendly. We managed to pick up a good few things that we needed that we knew we probably wouldn't be able to get elsewhere and went on our merry way.
We decided to go and check in the pound store to see if there was anything we could pick up there...and oh the things we found...card and paper for invites, packs of 40 compared to packs of 20 for £4.95 in the craft store...I know people will say 'oh but it's better quality in the craft store'...how do you know if you haven't tried it?...just because it's more expensive, doesn't automatically make it better...I buy many a thing from the pound store (iphone charger anyone?)...my 'official apple' one was thin and broke easily (replacement is about £30), whereas the pound store one is thick and sturdy.
We spent a total of £46 in the pound store and came away with 5 bags of goodies, centre pieces, invite supplies, decorations...so much!
If you are looking to DIY things and on a budget I highly recommend checking out pound stores...you may not getting everything you need but you'll get a good chunk.
Next stop eBay and Paper and String (awesome blog that I follow, go check it out!).