Specialty shops
A good tea shop is the only place where you can smell and taste before you pay, and for oolong that matters more than for most teas.
Roast level, the single biggest variable in oolong, cannot be judged from a photograph or a description.
Ask to try two roasts of the same tea side by side. A shop worth buying from does this without being asked twice.
The margin is real. You pay perhaps 30 to 50 per cent more than online for the same grade, and what you get is the tasting.
You also get an answer when you ask where the tea came from, and a shop that cannot answer is not a specialist.
Look at how the tea is stored. Loose oolong in an open bin under a light is being ruined in front of you.
Ask whether they roast in house or buy in. Roasters know what they have, and resellers often do not.
Buy your first 100 grams here, even at the higher price. It sets the baseline for every online purchase after it.
The last advantage is the bad batch. A shop you know takes back a tea that is not right, and a website rarely does.
Online
Online is where the range and the prices are, and it is where most of the disappointment happens too.
You are buying a description rather than a tea, and descriptions in this category are written by the seller.
The fix is to buy samples. Most decent sellers ship 10 to 25 gram samples, and that is the only honest way to start.
Look for a seller who publishes the origin, the roast date and the season. Three specifics is a good sign, and none is a bad one.
Photographs of the leaf tell you something when they are close up, and nothing when they are of the tin.
Postage changes the maths. A 50 gram order with shipping can cost more per gram than 150 grams bought in a shop.
Check the returns policy for a tea that arrives stale. Sellers who never have a problem sell a lot of stale tea.
Reviews help less than they appear to, because most buyers cannot tell a light roast from a stale one.
Use online to restock a tea you already know, and use a shop to find one.
Markets and direct
Tea markets have the lowest prices and the highest risk, and both of those are true at the same time.
You can taste before you buy, which is the same advantage a shop gives you, and you can haggle, which a shop does not.
What you do not get is any recourse. If the tea is not what was said, there is nobody to go back to.
The standard trick at a market is substitution: you taste one tea and are sold a cheaper one from a different tin.
Watch them weigh and pack your tea rather than accepting a bag already prepared under the counter.
Buying direct from a producer is different again. It works when you know the producer and it is a gamble when you do not.
Group buys and forum orders are the usual route, and they work when one person in the group knows what they are doing.
For oolong the specific risk is the roast. Tea roasted to hide poor leaf is sold at markets more than anywhere else.
Take someone with you who knows the category, or do not buy more than you would be willing to lose.
The practical mix
The sequence that works is sample online, confirm in a shop, then settle on one source for the everyday tea.
Start with samples from two or three sellers at the same stated grade, which costs very little and tells you a lot.
Take what you learn to a shop and ask for the same thing. If they can match it or beat it, you have found a supplier.
Then stop shopping around. One trusted source for a daily oolong is worth more than constant comparison.
Keep one online order a year for something unusual, and keep that order small.
Budget for the shop price on the tea you drink most, and for the online price on the tea you are exploring.
A reasonable split is 70 per cent of your spend with one source and 30 per cent exploring, and most people do the reverse.
Keep notes on what you paid and where, because after a year the pattern in those notes beats any review.
Whatever the channel, the test is unchanged: can they tell you where it came from and when it was roasted.