Yes, it will be enormously expensive to take a cab from YVR to Langley as it takes around an hour to get there depending on time of day, area of Langley, etc. That said, some options are to rent a car, or see if flying into Abbotsford airport would suit you--especially if you are flying Westjet-- it may be possible.
If you do need to stay in a hotel in Langley, the Coast hotel is very nice complete with a new casino complex underneath. There are also a couple of Best Westerns around too, depending on the area in Langley. Langley is spread out over the freeway, so you need to clarify what part you are looking at also. I'm sure if you go to hotels.ca or expedia.ca you can find something.