for just a home user you don't necessarily need raid if all you want is maximum drive space. if there is no worry of loss of data then you can just create a dynamic volume and keep adding disks as need to it....... the OS will handle up to 32 on its own before some other means, like hardware controllers is needed.
the system/boot partitions cannot be part of the volume as they cannot be on a dynamic disk, but all the rest can.
there is a few ways to approach this without any expensive hardware.
i have one machine built just for storage that is this way. only about $200 for base p4 machine, all was cheap. only real expense after that was the store drives.