This is ridiculous. How are you going to walk with one leg 8cm longer than the other? Most of the unilateral limb-lengthening is for people with length discrepencies.
When doctors do this for cosmetic patients, they usually recommend you do one leg, then the other leg in 2-4 weeks. This may improve your mobility during those first weeks, but the benefit is so immaterial. It will also cost a lot more (hospital stay, anesthasia fees, surgical/nurse fees). It doesn't reduce your chance of complication either, since you will make the same number of incisions and face the same set of complications eventually.
And can we stop the Parihar worshipping? The reason why most surgeons in the West are expensive is because of internal nails which is $35k by itself. Parihar charges $50k for his Precise procedures, while Turkish doctors charge the same amount. Giotikas around $60k and Betz around $65.
This rumor that Parihar isn't after money is such a joke. Charging $15k+ for foreign patients in India given the cost of nursing and hospital there is almost pure profiteering.