Lost OS X discs

Is there any way to get replacement discs that came with the macbook to reinstall the OS after switching out HDD's or reformatting? I know it was not the best to lose those discs but things happen and i need to know what i can do instead of buying the OS all over again... Have had the Macbook since June!

Contact apple they can probably help you out

Apple will sell them to you.. they usually are $15 a disc. My powerbook discs (2) after shipping was $35. You could also try ebay, that would be the cheaper option but who knows when or if they will be sold there.

Apple is your best bet.
eBay isn't a very good option in your case. Discs on eBay are more likely to be a PPC version of OS X which won't work with your machine. You need the Intel version of OS X, which still isn't available for retail sale. Not many eBayers will have the version you need, even if they think they do. From my experience, the vast majority of Mac and Apple software sellers on eBay don't really know much about them at all, despite their claims.

Give Apple a call.