About $23 for 5 quarts:
https://www.walmart.com/ip/Mobil-1-Advanced-Full-Synthetic-Motor-Oil-15W-50-5-Quart/20713647?wmlspartner=wlpaMy guess is that any major US brand of 10W-40, 15W-50, or 20W-50 is far better than whatever juice they came with from India. Certainly better than any oils from the 1940's when the Pre-Unit Bullet saw daylight, and definitely better than the 1960's oils that were about when Honda started selling machines by the tens of thousands that used common oil for the clutch, gearbox & engine. Engines that in most cases ran the cam bearing surfaces directly on the raw aluminum of the head. I have seen few Honda's that couldn't crack 50K miles with proper maintenance, and many that had over 100K.
B.W.'s recent experience with the cam followers in an Electra going belly up & eating the nose off of the cam is likely more about a possible factory defect in the follower or improper valve clearances than a direct lubrication failure. We're awash in good oils, but there's only so much even the best oil can do. Keep clean decent quality oil in your beast & change it often.
The only real slickum-voodoo juice I've ever seen actually work is the "Lucas TB Zinc Plus", which just as Bilgemaster says cuts the valve adjustments way down in the Pre-Unit Bullet, so it definitely is doing something. Sadly it probably wouldn't be a good plan for the wet clutches in the lighter-weight modern unitized construction "common oil supply" designs. But for dry-clutch designs it would likely be beneficial.