~I was posting this for the 2005 joined Noob, but Chia nuked the thread~
If your bike is liquid cooled, and never used at redline (at the track day), then you can stop spending $20 a liter on Motul 300V. Unless you own a Ducati or Aprilia, they have to run on synthetics.
That being said, the fan on my GSXR used to pop on in traffic, was running hot now and then in the bullshit. I switched to the 300V and it cooled the bike a lot more efficently, the fan almost never needed to come on. I used to wring the neck on that bike, beating it hard, so I was stressing the engine. Never missed a beat.
I used to run the Castrol M/C oil from Canadian tire in one of my old bikes, CB900F, mostly cause it burned it. 6.99 vs 19.99.
Only thing I recommend 300V for is air cooled bikes that do a lot of commuter duty (idling in heat) and full blown race bikes. The sheeple can get by on the cheaper stuff for sure. It's the same with chain lube. I've seen a buddy use nothing but WD-40 and get 50000kms out of his chain on a ZX6R and another guy run PJ1 and his lasted maybe 10000kms.
There is no right answer, it's what's right for you.
Think about this. There is a big difference between the urban commuter guy and the weekend balls out guy. The urban guy gets up to head to work, his bike is flashed up and he's off, nary 30seconds to warm the oil, and he's reving it down the road, then idling, then going again. Maybe 15 min he's at work, shuts the bike down. If that oil doesn't get hot enough to even burn the condensation out of the block, you can look at his sight glass and see the water forming inside the oil, the chocolate milk effect. Had this guy warmed his bike up to operating temps first, then rode it harder or even longer than that, his oil would last longer.
The weekend warrior is a bit different, usually anal about his shit, he's got the bike warming up while he goes back in to gear up or checks his tire pressures again. Then he heads out and revs the can off the thing all afternoon, only stopping to put premium fuel in the bike and shitty coffee and eats in his belly. (this is what sport bikes are for)
OP has to recognise which guy he is and spend money on oil accordingly. We'll keep saying it, motorcycles are not a welfare sport, take the fucking bus if your bank roll can't handle $100 oil changes and $600 tires every 5000kms.