如何使用 Claude 作為旅遊預算規劃工具：Elena Skill 指南

It can do the structural half well and the numeric half not at all. It knows a trip has an airport-transfer line and a laundry line and a Sunday-closing problem, which is genuine recall over a huge body of trip write-ups. It does not know what any of those cost this month, because it has no live prices - only an average absorbed at training time, across seasons, neighbourhoods and traveller types, in a currency that has since moved. Use it for the lines and the consequences, and supply the numbers yourself.

Rarely because of a bad estimate. Almost always because of second-order costs created by a decision you already counted as a saving. The flight that saved sixty euros lands after the last train, so it costs a taxi. The hotel that saved thirty a night is twenty minutes out, so it costs two journeys a day for six days and changes where you end up eating. None of these are surprises - they were determined at booking. The useful question is not what will things cost but what has each decision already committed me to.

Because the damage is not the inaccuracy, it is the anchor. Once it tells you to budget eighty a day for food, every real price you see gets judged against a number that was invented, and you start making real trade-offs against it - skipping the restaurant you came for because it feels like an overspend, or feeling comfortable for five days and broke on the sixth. An inaccurate estimate you can correct. An anchor rearranges your decisions without you noticing.

Look up three real prices yourself before you prompt anything: one specific flight, one night at the kind of place you would actually stay, one ordinary non-touristy meal. Ten minutes of work. Then have the model build everything else as ratios to those three anchors, showing its reasoning, with an explicit look-this-up line for anything that cannot honestly be derived - entry fees, transfers, tourist taxes. You get a model you can argue with rather than a total you have to trust.

A percentage is a ritual rather than a plan. Fifteen per cent that one missed connection would swallow is not a buffer. Ask instead for the three most likely ways this particular trip overruns, what each costs relative to your anchors, whether it is avoidable at booking or only manageable once it happens, and what you would actually do in the moment. Then size the buffer to absorb the two most likely without changing the trip. Derived rather than rounded.

The local one, always. When a card machine offers to charge you in your home currency instead, that is dynamic currency conversion and the rate is set by the merchant's provider rather than by your bank. Which? documented a Ryanair booking converted at 93p to the euro when Visa's rate that day was 87p, about nine pounds on a single transaction, and their advice is to always pay in the local currency and let your card provider do the conversion.

The handling itself. Foreign transaction fees on your own card, whether cash withdrawals are charged differently from purchases, ATM fees, currency you convert back at a loss, and whether the destination is card-first or cash-first in practice. None of this appears in a normal budget and a model will not raise it. Plan how you will pay separately from what you will spend, and get the fee answers from your own bank rather than from a chat window, because it does not know your bank.

Only if you travel more than once or twice a year, and then clearly yes, for one reason: reconciliation. A budget only becomes accurate when it is built from what you actually spent last time rather than from an average of strangers. That requires a record of planned against actual, per line, with the destination and month attached. A one-off prompt produces a decent structure for the trip in front of you and remembers none of it.