I've had a 13 this year and where I've been I hang out round the corner with it early to get it as soon as it 'switches' to S or SW ..so I usually get the first few hours in with it before it 'goes up' ..escalates...
Which has been great as I manage to get a few hours in before some beaches get jammed packed with all the new foilers..kites and windsurfers these days..(respect to them)
In regards to selling gear it's coming towards end of season then... it would sell better on east coast as season comes on there...probably...
Buying it is easy peasy so many good kites around at the moment as everyone's going 'foiling' you could pick some really good 2018 ones up for 200$ or less
Board also.
Too many to bring on a plane methinks..

7...9..13...is good