You probably should ask him more details about his system, without seeming too suspicious. If he has the ATI TV card and he's already using that for capture, another capture card won't be much of an improvement (plus all the headaches of tweaking new drivers - video editing hardware can be finicky).
If by any chance he has a miniDV video camera and doesn't already have a firewire card (or port on his motherboard), that might be a good choice...so he can step up from analog capture to digital.
Videoguys has a couple solutions in your price range, including the ADS Pyro card and Pinnacle's Studio DV (which comes with a firewire card). Most retailers will also have a few reasonable firewire cards.
As others have said, a hard drive might be the best and safest choice. Doing video work, you can never have enough storage space, so you can't go wrong with a hard drive. (...unless he already has all of his 4 ATA slots occupied by hard drives and optical drives.)