fee-analysis

name	fee-analysis
description	Use when advertised flight price seems too good, or when comparing LCC vs legacy carrier total costs. Triggers on hidden fees, baggage cost, true price, real cost, checkout surprise.

Fee Analysis - Phân Tích và Loại Bỏ Phí Phụ Thu

Purpose

Airlines - especially LCCs - intentionally show low base fares then add fees at checkout. This skill strips away the deception, calculates what you'll actually pay, and re-ranks options by true cost. A $89 Spirit ticket that becomes $275 after fees loses to a $189 Southwest that includes everything.

Input Required

• flight_options[] from flight-search skill
• baggage from traveler profile (carry_on | checked_1 | checked_2)
• loyalty_programs[] from traveler profile
• preferred_payment (credit card type, if known)

Execution Steps

Step 1: Load Airline Fee Matrix

Read references/airline-fee-matrix.md for comprehensive fee data by airline.

Step 2: Calculate True Total for Each Option

For each flight option, compute:

true_total = base_fare
           + taxes_and_surcharges
           + carry_on_fee          (if LCC and carry_on not included)
           + checked_bag_fee       (× number of bags × number of passengers)
           + seat_selection_fee    (if desired, per passenger)
           + meal_fee              (if not included, long-haul)
           + change_fee_risk       (weighted by probability from flexibility-analysis)
           + payment_surcharge     (credit card fee if applicable)

Step 3: Fee Breakdown Table

Present each option with full fee breakdown:

Fee Breakdown: HAN → SFO, 2 Adults + 1 Child

                    Option A (VietJet)    Option B (VN Airlines)   Option C (Korean Air)
Base Fare           $380 × 3 = $1,140     $620 × 3 = $1,860       $580 × 3 = $1,740
Tax & Surcharge     $95 × 3 = $285        $120 × 3 = $360         $110 × 3 = $330
Carry-on (7kg)      Included              Included                 Included
Checked Bag (23kg)  $45 × 3 = $135        Included                 Included
Seat Selection      $12 × 3 = $36         Free                     $15 × 3 = $45
Meal                Not included          Included                 Included
Payment Fee         $0 (debit)            $0                       $0
─────────────────────────────────────────────────────────────────────────
TRUE TOTAL          $1,596                $2,220                   $2,115
Per Person          $532                  $740                     $705
Rank Change         Was #1 → Still #1    Was #3 → Now #3          Was #2 → Now #2

Step 4: Identify Rank Reversals

Critical insight: When true_total changes the ranking from advertised price:

⚠️ RANK REVERSAL DETECTED:
  Option X was ranked #3 by advertised price ($89)
  After fees, it's actually #5 ($275)
  Option Y was ranked #5 by advertised price ($189)
  After fees, it's actually #2 ($189) - no hidden fees!

Step 5: Fee Avoidance Strategies

For each applicable fee, provide actionable avoidance advice:

Carry-on Fee (LCC):

• Pack within airline's free personal item dimensions
• VietJet: 7kg carry-on included; Spirit: personal item only (45×35×20cm)
• Consider: Is the carry-on fee still cheaper than a legacy carrier total?

Checked Bag Fee:

• Airline credit card: Many waive first bag (e.g., United Explorer card)
• Status match: Silver/Gold loyalty = free bags
• Pre-pay online: Always cheaper than airport counter (20-50% savings)
• Ship luggage separately: Services like LuggageForward for long trips

Seat Selection Fee:

• Skip it: Accept random assignment for savings
• Check in exactly at 24h mark: Best free seats available
• Back of plane: Often free even when front costs extra

Change/Cancel Fee:

• Book with credit card that offers trip protection
• Some airlines (Southwest, JetBlue) offer free changes
• 24-hour rule: Most US carriers allow free cancellation within 24h of booking

Payment Surcharge:

• Use debit card (many airlines waive surcharge)
• Some airlines charge extra for credit card (Ryanair, AirAsia)
• PayPal sometimes adds processing fees

Step 6: Cabin Bag Size Reference

Include for options with strict carry-on policies:

Airline	Personal Item	Cabin Bag	Weight Limit
VietJet	36×23×56cm	7kg total	7kg
AirAsia	40×30×10cm	54×38×23cm (paid)	7kg
Spirit	45×35×20cm	56×46×25cm (paid)	None stated
Ryanair	40×20×25cm	55×40×20cm (paid)	10kg
Southwest	No limit	61×41×28cm	None stated
Vietnam Airlines	56×36×23cm	12kg (economy)	12kg

Step 7: Output Summary

ORIGINAL RANKING (by advertised price):
  1. VietJet $380    2. Korean $580    3. VN Airlines $620

TRUE RANKING (all fees included):
  1. VietJet $532    2. Korean $705    3. VN Airlines $740

VERDICT: VietJet remains cheapest even after fees (+$152 in extras).
However, VN Airlines includes lounge access with Business Saver 
that isn't captured in this analysis.

Limitations

• Fee data is based on published policies - airlines may change without notice
• Some fees vary by route, booking channel, or time of purchase
• Loyalty status benefits are estimated - check your specific tier
• Meal costs for LCCs are not included (varies too widely)