Mia spent a total of $30 per siblings * 3 siblings = $<<30*3=90>>90 on her siblings.
She therefore spent $150 total spending - $90 spending on her siblings = $<<150-90=60>>60 on her parents.
As each parent received an equal amount, each parent’s gift cost $60 total spending on parents / 2 = $<<60/2=30>>30.
#### 30