I've never heard of Trav being the "official" abbreviation for Travel.
It's not bad for a hand registered name, but also not one that you can really market to anyone, since it's not much of an exact match search term.
You mention travel insurance being a $10 billion industry, but as a consumer, are you going to buy travel insurance from a reputable financial institution or insurance broker, or are you going to get it from a site called TravInsurance...?
It's one of those tough ones... big market, sure, but how does a domain name like this see a piece of the action?
I think you're best off listing it and asking for low to mid $XXX. Someone could like it as a brandable type.