A low airfare is a useful starting point. It becomes a poor comparison when one price includes the trip you need and the other includes only permission to begin assembling it.
Cheap flights can still be genuinely cheap. The job is to compare equivalent journeys, rather than adding every optional extra until a low-cost airline looks bad on principle.
Pack before comparing prices
Ryanair’s published baggage rules distinguish the included small personal bag from additional cabin and checked baggage. Its small-bag dimensions are 40 × 30 × 20 cm; Priority adds a 10kg cabin bag subject to its size rules. Check the terms applying to the booking, since baggage rules and charges can change.
The practical question is what your trip needs. A weekend with an under-seat bag is not equivalent to a week with sports equipment. Price the bags you actually intend to take on both legs before deciding which headline fare wins.
Compare one person, one complete return trip
Illustrative worked example — fictional fares, not live airline quotes. Two airports serve a destination. Assume the same travel dates, suitable flight times, the same baggage needs and no need for a paid seat choice. All amounts below cover both directions, with taxes and unavoidable booking charges already included in the stated fares.
| Cost | Lower headline fare | Higher headline fare |
|---|---|---|
| Return airfare | £60 | £120 |
| Required baggage for both flights | £50 | Included |
| Home-to-airport return travel | £35 | £20 |
| Destination-airport return transfer | £40 | £12 |
| Complete transport cost | £185 | £152 |
The £60 fare produces a trip costing £33 more. But change the baggage need and the answer changes: with only an included small bag, the first option falls to £135 and becomes £17 cheaper.
This is why “low-cost airlines are a false economy” is too broad. The traveller’s requirements determine the comparison. Keep optional seat choice, food and other extras optional unless they are actually necessary for your party.
Time and timetable risk belong beside the price
Suppose the cheaper airport adds an hour each way. Record two extra hours separately from the cash total. You might happily exchange them for a saving, particularly if the transfer is straightforward. Someone travelling with a tired child may make a different choice.
Check the return timetable as carefully as the arrival. An airport train that stops before your flight lands is not a usable transfer just because it appears in a fare search. If a late arrival requires an overnight stay or taxi, use a realistic quote and explain which scenario triggers it.
Do not pretend a disruption contingency is a certain cost. Show a normal plan and an adverse case. A non-refundable onward ticket can make the downside much larger than its purchase price if the connection fails.
Four passengers do not multiply every cost by four
Flight fares and per-person bags may scale with the party. A taxi, hotel room or shared checked bag may not. Calculate quantities explicitly.
For example, an illustrative £48 taxi shared by four costs £12 each. Four separate £15 bus fares total £60. That does not prove a taxi is always preferable: luggage capacity, child seats, booking fees and availability still need checking. It shows why comparing a whole taxi price with one bus ticket answers the wrong question.
The same care applies to departure airports. Parking may cover the whole car, whereas rail tickets are per person. Count the whole party’s trip before dividing by people if you want an individual budget.
Save the checkout comparison
Before paying, record the final total, baggage allowances, airport names, travel dates and relevant change or cancellation terms. Compare those totals in the same currency and include any payment conversion cost that applies to you.
For a package holiday, establish whether transfers and bags are already included before adding them again. For separate bookings, check how each part behaves if the flight time changes. A slightly dearer fare may buy flexibility, but that benefit should be identified in the actual terms.
The best result can still be the cheapest headline fare. When it is, you will know why: your luggage fits, the airport works and the transport total stays low. That is a stronger bargain than a price that only survives until the next checkout screen.
