Yes, the excess is £4.50 (the full difference)
Half the difference for change of route/overdistance.
Full difference for change of ticket type.
(If you change the route, the ticket type can change if appropriate, and you are not penalised and still only changed half the difference)
Note that not everyone knows how to do excesses, and not everyone can do it correctly.
York station should be fine though.
BML - NOT
SCO - SUP OFFPK DAY R EMT
00000 - ANY PERMITTED
1 Adult @£ 15.50 = £ 15.50
BML-NOT
CDR - OFF-PEAK DAY R EMT
00000 - ANY PERMITTED
1 Adult @£ 20.00 = £ 20.00
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