Without checking the latest edition of "Emily Post" I would ask how close is your husband to this cousin? Is this a first cousin or some one once-removed? In my opinion if this cousin was someone your husband grew up with and was a significant part of his life, you are "obligated" to send a higher end present for both the shower and the wedding. A nice kitchen appliance like a blender or toaster or linens would be appropriate for the shower, and chrystal, china, or a significant gift certificate would be appropriate for the wedding. Also take into account the venue and customs of the family. If they are more laid back, choose items that would be fitting.
Even if distance is an obstacle...if this cousin is someone you'd be otherwise seeing at every holiday and family gathering or the annual summer visit...nice, well-thought out presents are in order! Most important how close are your husband's parents to this cousins parents? Afterall, we're not just talking about ettiquette and protocol..we're talking the all too dreaded family politics. No need to get your husband's aunt or uncle in an uproar let alone your mother or father in-law because you didn't send their future in-law a decent shower gift. This simply would be a "faux pas" especially if this cousin is a first cousin.
If he (your husband) only kinda knows this cousin...has no childhood memories, hasn't a clue what his cousin's middle name or date of birth is, and sees them only at funerals and rare family reunions, I'd say a single wedding present for the actual wedding day would be appropriate...and something in a more modest price range such as a picture frame or a nice photo album.