Quick quiz: You've got a windfall of close to $600 to spend on wine. Will you:

a) Fulfil a lifelong dream with 200 litres of Fruity Lexia.

b) Treat yourself to a special case from a favourite vineyard.

c) Splurge on a single icon bottle.

If you answered a) with a view to hosting an epic round of Goon of Fortune, you're not the target market for the latest – and possibly priciest – wine-saving gadget to arrive on our shores. The Coravin Model Two Elite for screwcap ($559 plus GST) is for well-heeled wine fiends who open the good stuff without waiting for friends to come by – and whose partners, doctors or better judgment advise against finishing that flash bottle within a night or two.

The pitch: "Sample, pour and enjoy any wine – without committing to the entire bottle." Pour a glass and return the bottle to the fridge or cellar for up to three months. "Once accessed with Coravin, wine can continue to be stored and preserved as if it was never open."

How it works: A Coravin device stops wine from being exposed to air – and hence from losing freshness and character – by piercing the bottle closure with a thin, hollow needle. You press a trigger that forces the wine out through the needle, simultaneously replacing it with protective argon gas.

What you get: Our Coravin for screwcap package came with the device, two argon capsules, a protective bottle sleeve and two special screwcaps – one standard diameter, one large.

Easy to use? Yes, although getting started requires following Ikea-esque illustrations. The original Coravin, as seen in restaurants in recent years, sticks the needle directly through corks so that bottles are never opened. Coravin for screwcap is the same device but before inserting the needle (or pouring any wine) you swiftly swap the original screwcap for a Coravin screwcap, which has a silicone membrane that can be penetrated by the needle.

We tested: Cullen Diana Madeline cabernet sauvignon 2014 (about $115) and Giant Steps Lusatia Park chardonnay 2015 (about $50).

For how long? At intervals over two weeks.

Did it work? Extraordinarily well, streets ahead of any other wine-saving equipment we've tried. For both wines, there was no discernible difference in the glass when the wine was poured on the second, third and seventh nights. We then left the bottles (by now less than half full, normally bad news for wine) for a further week. At the end of the second week the cabernet sauvignon smelled the same as when first opened and showed no signs of oxidation. With the chardonnay we applied an additional test: we poured the last glass of chardonnay in the bottle and sampled it against a glass from a freshly opened bottle of the same wine at the same temperature. They smelled identical. On the palate, the Coravin test bottle tasted a little less bright than the one opened minutes earlier – but so slightly we're quibbling.

Can you use this version of Coravin on a bottle sealed with cork? Yes. Just follow the instructions for inserting the needle into cork and don't use the special screwcap.

What about champagne? No, but the Coravin people are working on it.

Worth it? At home? If you're a wine tragic trying to drink "less but better" and lack enough wine-freak friends with whom to share your excellent cellar, yes. (Coravin was invented by a wine nut when his wife was pregnant.) Otherwise you'll be in the drinks trade, selling great wines by the glass that you want to keep in condition.

Worth knowing? Each glass you pour costs – roughly – about a dollar's worth of argon. Refill canisters good for about 15 150-millilitre glasses are about $30 for a two-pack. Bear in mind when wondering if any given bottle warrants this treatment. When you pour the last glass, take off the screwcap (or cork) – no point squeezing gas into an empty bottle. Extra screwcaps of either size come in six-packs for about $45.

Note: there are less expensive Coravin models: at $549 (plus GST) the Model Two is functionally the same as the Elite but with less fancy finishes. The Model One has slightly different technical specifications but does the same thing and comes in at $339 plus GST.