SQ costs more if booking a reward seat..

On the back of the recent announced Y reward seat sale, did some dummy bookings..and compared same dates/flights for both Miles and straight PE purchase. MAN-MCO

SQ (Virgin fuel/ insurance surcharge)
PE Bought seat = £213
PE Reward Seat = £233

Also, the reward seat doesn't show cost for:
US Transportation Cost - £21.20
Passenger Facility Charge - £2.90

However these applied to the PE purchased seat ?|

Overall costs for Tax/Surcharges etc:
Reward booking = £393.09
PE Purchased = £397.19

You could argue that the reward seat is therefore cheaper, but strange goings on....
Does it cost more to book a reward seat?
Are reward seats not applicable to some US charges??