How often to you get your kid's picture taken?

My daughter is 2 now (as of yesterday) & we just take photos of her with the digital camera. For her first Christmas we had a professional photo taken with Santa at the Myer department store, we didn't worry about it for her 2nd Christmas but this year there will be a sibling for her so we'll have a photo with Santa taken of the 2 of them so that will be good. Oh we also had a heap of professional photos taken just before her 1st birthday but i only purchased 1 design in a couple of sizes & got a small photo for free is a different design but they were expensive on their own so we had no intention of buying many nor would we be likely to do it again - unless we wait until the kids are a little older & have a couple of nice ones taken of the 2 kids together but being so dear, i'm not really sure. I doubt it though, they're just too dear & i already bought a fancy photo printer so i could take the photos myself & have quality pictures without the huge expenses.