It's true, Allegiant Air has some decent priced flights ranging from $99 to $154+ each way. However, Bellingham is about 1 hours drive from Vancouver and customs can be a hassle. Border line-ups can be a problem too. For some reason, Canadian customs like to give us a bit of a hard time when we return from a US airport.
I called Bellingham Airport and they don't have secured parking,which surprises me.