I use the cheap ammunition when tuning. You can do a couple shots of the good stuff over the chronograph, then a couple of the cheap stuff to get the general speed difference. I'd rather pump 1000 rounds of premier hollows at $6.25 a tin rather than 1000 rounds of JSB's at $19 per tin. Once you get the general speed you want, you can finish fine tuning with the JSB or other premium ammunition.
Just bought 4 tins of these so I can tune a gun that should be here shortly. If I can put all 4 through the gun, the barrel will be broken in and the gun ready to shoot.