Recently airlines seem to have ratchetted up auxiliary fees to the point that the final price is often 50%-100% higher than the advertised price. The fees are primarily cabin baggage, checked baggage and seat selection. These fees can vary a lot from airline to airline and are often difficult to determine up front. In some cases they are not disclosed until after you have booked ("you can choose your add-ons later").
Example of a specific search: roundtrip Berlin<->Boston, Oct 13, 2023 to Jan 10, 2024 +-3 days for both departure and arrival. 2 passengers, 1 checked bag each, no overhead carry-on, minimal seat reservation (so they can sit together, no fancy seats). Currently the best option I found is $604 on Delta, but it was very difficult to find.
A few search engines that I tried:
- ITA Matrix : has (surprisingly) zero support for auxiliary fees and also doesn't search budget carriers like Play Air or Norse Atlantic
- Google Flights : It has a bag filter but that only allows to add carry-on, not checked bags (on this specific search).
- Momondo, Kayak, Beat That Flight They do have checked bag filters but they don't work for the +-3 day matrix. Either the matrix disappears or the displayed prices are not available if you click on a specific date.
- No engine seems to have any means of incorporating seat reservation fees (if required to sit together)
- What are some tips and tricks for finding the cheapest flight when luggage and other fees are not revealed until far into the booking process?
- Are there any flight price search engines with baggage allowance included?
These are both fairly old, fees have gone up a lot recently and none of the answers provided did what I was hoping for (find lowest price over a certain date range)
Question: how to compare flight prices including checked bag fee and minimal seat reservation privileges over a date range (+- 3 days or there abouts).