I second Fery Khani. Though contamination due to pipeting increase but are still avoidable. $-5 times pipetting in and out is enough for mixing ang this time consumed is afforedable. But during vortexing, shearing and degradation of RNA will give you more important loss (RNA).
Yes, Fery is correct. Just one more note of caution. If you're looking for RNA longer that 20kb, you can potentially shear your RNA by pipetting (this is more common with DNA, but we've seen it with large viral RNAs). Something to keep in mind.