Not unusual. It is called an 'accompanied travel' fare and is only available if the rules are met (in this case, at least 2 people on the booking).
Code:
V FARE BASIS BK FARE TRAVEL-TICKET AP MINMAX RTG
55 PXRCCP13 P R 1888.00 T30JN 7/3 10/12M AT01
PASSENGER TYPE-ADT AUTO PRICE-YES
FROM-YTO TO-ROM CXR-AC TVL-19OCT17 RULE-E390 IPRAI/101
FARE BASIS-PXRCCP13 SPECIAL FARE DIS-E VENDOR-ATP
FARE TYPE-BAP RT-BUSINESS CLASS ADVANCE PURCHASE
CAD 1888.00 1401 E14JUN17 D-INFINITY FC-PXRCCP13 FN-3H
SYSTEM DATES - CREATED 13JUN17/1154 EXPIRES INFINITY
13.ACCOMPANIED TRAVEL
MUST BE ACCOMPANIED ON ALL SECTORS IN SAME COMPARTMENT
BY AT LEAST 1 ADULT PSGR. NO MORE THAN 8 ACCOMPANIED
PASSENGERS PERMITTED FOR EACH ADULT PSGR.