Thank you for your question and sharing your reasonable doubts !
Most good Rhinoplasty surgeons nowadays are just that ... good Rhinoplasty surgeons consistently achieving safe predictable satisfying results. The patients should be informed of the implications of the two techniques and in case of an open approach it would be a good idea to show a range of the columellar scars in your hands. It would also be a good idea to have the flexibility of rarely changing between the two approaches if it is considered to be better for the patient. There is no reason for a cost difference between the two approaches as long as a surgeon achieves. consistently good outcomes through the approach of their choice.
Regarding suboptimal correction ... that may happen through either approach.
I hope that helps.
Best !