What about those plastic ones with spigot and natural carbing?
???????? No idea...
With natural carbing though...Carbonation is only half the issue with the "gas" side of things. Yes you absolutely can naturally carb a keg, (many here do that exact thing) but you will still need gas to push out the beer. It's the same principle as cask wine, or the plastic containers of water that have a dispenser tap on them. A wine cask will pour great for the first half of it, but then slow down considerably as it empties. The water containers typically have a spot on the top where you are supposed to puncture the container. This allows air in to the vessel and then pushes the rest out.
Yes the cost of kegging to setup can seem very daunting, but it is so worth it. And for me, none of it has to do with the "coolness" factor of pouring a beer. Once your mates have had a few goes at your taps, the novelty wears off. For me, it's the convenience. One vessel to fill, one vessel to clean, one vessel to store. NO big cleanup after a poker night when the last thing you want to do is go back out to the shed and pick up and clean all the empties with a massive hangover....
The practicality of kegging is why i do it. I still bottle the odd batch here and there 'cause lets face it, i don't just drink at my house...
Small chest freezer or a fridge for the kegs - free quite often. Keep eyes peeled.
Get a kegging setup from a sponsor or other home brew shop. Cost depends on how "big" you go...
Gas - i've been kegging for over two years now, and have only just swapped over my first gas bottle. As it turns out, it still had a kilo or so of gas left in, but i had a party to cater for and didn't want to chance running out. I get mine from BOC. A refill i think is about $65 and the rental on the bottle is $13 a month. I'm sure there are cheaper ways to do this, but i live in a "regional centre" as opposed to a city, and options are severly limited to me for gas.
All up, i reckon it cost me around $1000 to start kegging, but that was including a chest freezer purchased brand new ($300)
It is worth it if you can part with the cash to do it.
Cheers,
Nath