If you want to try some better ammo without buying a brick, I suggest contacting Asmir at Tesro. He’s in Ottawa and offers different levels of sampler packs with various brands and price levels. Get to try all the flavours
It's not a bad idea, although I'd still have to get a brick - the sampler packs come with 10 boxes each.
Also, given the run of the mill rifle I use, I'm not sold on the necessity to test a large variety of ammo. It looks like Eley Club or Sport will let me reliably shoot .75" @ 50 yards.