Due to the bluevm LA location's poor network, I raised a tk to request migration with few data. After two days, their support finally replied to me
There will be a $5 charge for this, we don't migrate cheap yearly plans.
I recall they support free migration last year. And my service goes to blue4 2G, I don't think it is cheap yearly like $5/y. Tried other providers, they migrated my vps with data for free. Really disappointed for their policy.