In message , at 11:42:58 on Fri, 16 Jan
2015, tim..... remarked:
3 months travel card zone 1 to zone 6, works in underground, overground,
buses, and railway trains. It will expire on the 31/03/2015. Great
value, if you use public transports regularly in London. Call
07930056188 if interested, (I won't reply to txts).

You know they are (a) partly refundable, and (b) not transferrable,
right? So it's illegal for you to sell it,

pedantically

is it illegal for him to sell it for whatever it is worth to the buyer?

Of course, as it is linked to a specific numbered photo card, that
value to someone else is going to be no more than "interest" value

As far as I know an adult Travelcard within z1-6 bought at a TfL ticket
office is the one ticket of that type which doesn't require a photocard.
--
Roland Perry