Going back to the OP - would I be right in thinking the KK are slightly thicker plastic then the cheaper ones? Depending how long you are planning to mature them in the kegs then the thicker plastic can be better, as doesn't allow as much air in through the thinner plastic (would you notice the difference?). For starting up the budget barrels will be fine but generally you just tend to "upgrade" to cornies over time. I've not been brewing that long and had a big gap from moving house and still haven't got set back up. I started off with one kk as part of a package I got as I gift in my early 20s, I now have 3 kk top taps had all delux taps and pressure gauges fitted (in hinde side I wish I had gone with the bottiom tap, no float to mess around with, pressure gauges waste of time leaked more and the plastic broke and the delux tap whilst looked good didn't make any difference for the cost) I now also have 3 cornies a large bottle of c02 (currently empty) and a gas management board all of which hasn't been fully installed. Again these arn't with their draw back I don't force carb instead rely on natural condition I need to change the seals over though to the red ones which require less pressure to seal, they can also leak gas too.
When I get set up again, I might try the plastic pub style pins they're 4.5g at £30 ish quid there's an article with the link to a supplier on the "how to" guide and I think these could be really good for homebrewing, provided of course you can drink them in a week or so with a cask breather.
