Yes, about £40 if you do it yourself.
Remember that you will need to reload your OS and all applications, and will have lost all your data from the old hard drive. Also, dependent upon the laptop you might need a 2.5" SATA or a 2.5" PATA drive (or even maybe a 1.8" drive if you've gone for a mega-tiny laptop). Hence quoting the make and model of the laptop here would help us identify which drive you need to purchase.