As far as different quality from Eley goes I  read an article some time ago explaining some differences in production. For the 2 top grades they buy in billets of lead to their own spec, skim off the top of the billet to remove any possible impurities and then make the bullets which of course are a different profile to the others. The lesser grades are swaged from bought in wire. 
The Lube is also different on the top 2 grades from the rest. The ammo is constructed on separate dedicated machines, batch testing then separates the Tenex from the  Match. These are then packaged with the average velocity for each lot. As less is produced in this way another reason for higher unit cost. I  can not remember the other differences but I will try and find the article again.
I find that out to 50m Club is fine but at 100/200 Match will produce a tighter group even in the old Martinis that I shoot  TJ.

I have been round the Eley factory. As stated, the lead comes in in billets from a metals specialist. It is then extruded and coiled in one operation. The coils of lead go into bullet swaging machines, but the process is different for the higher grades. For grades such as rifle club, the bullets and cases go into hopper fed machines where from where they emerge as finished rounds. Tenex and Match are quite different--the process is closer to hand-loading. Cases are weighed and batched in trays, bullets are graded by weight and then inspected by a computer system with vision. any minor visible defect causes the bullet to be ejected from the tray. The cases are primed and spun to move the dry powder into the rim, after which a single, metered drop of water is added to the priming powder to activate it. Every stage of the assembly is inspected with great care and samples are taken for laboratory checking at each stage. Range testing determines wether the ammo will "make Tenex" or if it is to be sold as a lower grade. Lubrication is the last operation before packaging. All this care accounts for the high cost.
Fred.

Fred,

I’ve always been curious as to how rimfire cases were primed; long ago my father told me that the old cases were primed by putting a drop of fulminate into a spinning case and so inertia pushed the priming compound into the rim. More recently I’ve taken some rimfire cartridges apart and apparently they had put a little round wafer of fulminate into the case before the rim was formed, and then sized down the case forming the rim and crimping the wafer into the rim, or at least that what it looked like to me. Thanks Fred!

Bob