I am looking at different routings to LCA. On a full J fare of around £600 o/w, I can usually route through any of the nearby hubs - TLV, DAM or BEY - and continue the short hop to LCA on CY. Combining the full J fare with a D or I for the return journey (on the direct LCA_LHR flight) usually gives an all-in fare of around £900.

I can see a good connection via CAI this time, and get the same LCA (JFLRT fare basis) fare to route LHR-CAI-LCA. However on this routing, there is a surcharge of NUC (USD?) 630 with the note "Circle Trip Minimum". Any idea what/why this is? Is this due to exceeding the maximum mileage permitted on a LHR-LCA fare?

Fare (A1): BA LONLCA JFLRT fare (rules) £642.60
Fare (A2): BA LCALON DEUNBA fare (rules) £261.00
Tax: United Kingdom Passenger Service Charge £13.00
Tax: United Kingdom Air Passengers Duty £80.00
Tax: Service Charge at Cairo Airport $1.00
Tax: Egypt Embarkation Tax $15.00
Tax: MS YQ surcharge $2.50
Tax: Cyprus Airport Service Charge CYP 8.00
Tax: BA YQ surcharge £43.00
Surcharge: Circle Trip Minimum NUC 630.96
Total for 1 adult passenger: £1378.60