Frugal scrapbooking? What a trendy phrase! Yes...you can do it cheap. I used to live in the "boonies", 40 miles from the nearest
walmart (which had a paultry scrapper department...unlike most). I usually went online at Jo annes and signed up for their mailing list. They sent my coupon codes and whenever they sent one for free shipping, I'd usually stock up. However, I have to say, the in-store deals are much better. They keep a line of 12 X 12 post bound albums that have 5 refill pages and a protective cover. Several times a year (I think when the seasons change) they clear out their stock by offering them half price...which makes them only 4.99! I buy multiples b/c I give them as christmas gifts.
Don't start out with the 8 1/2 by 12 size thinking you'll save money. The truth is, b/c most ppl work with the larger size, thats where all the deals are to be found. Another poster mentioned the paper packs that frequently go on sale for $10. There is 180 pages there! I have three of these books. I could be locked in this house for the next two years and I'd run out of pics before I'd ever run out of paper.
Often I examine things I'd normally throw away. The extra buttons that come on shirts, confetti, cards, charms that have fallen off of jewlery/clothing. These make great, FREE, add ons. I also raid my moms fabric room. She has a great big cabinet full of scrap lace and ribbon. I about choke when I see these specialty cards with about 5 specialty yarns/ribbons (probably only about 12 in of each) b/c they cost like $13! I could buy the whole spool of ribbon for a fraction of that...why are ppl paying so much for pieces??
When you travel, keep your eyes open for scrap stores. I was in Destin a few months ago (not really traveling, but it is a travel destination) and I stumbled upon a joint called the Scrapbook Clearance Center. I got a huge bag of stuff for $25.
Once you've established what materials you use MOST frequently, buy in bulk when you find the item/s on sale. For example, if you like using stickers and you find yourself repeating a certain theme (like beaches, I live near them so they're in a lot of my pics), if stickers are half off, pick up a variety of stickers in that area. Don't buy soccer stickers just b/c they're cute and on sale (I've done this) if you don't know anyone that plays soccer. (I WILL USE THOSE COWBOY STICKERS ONE DAY

)
Learn one new trick at a time. Each "area" of scrapbooking means new tools AND supplies and obviously more money. SO, I advise you research and be sure what you want to do next before investing the time and money. (Examples: stamps, embossing, eyelets/grommets)
Scrapbooking is addictive...which is why it is so expensive. Every year I bring home more supplies than the last, yet I don't scrapbook any more or less. You just see neat stuff that you know you'll use eventually...bring it home, and it gets burried and you forget you even have it. If you're an online shopper I suggest you stay away from ebay.