Listing fees are charged regardless if an item sells or not (and higher start price normally means higher listing fee, think it's fixed rate-ish for buy it now stuff though).
I seem to get 20 free listings a month though (still have to pay final value fees). Perhaps through the mobile app or something.
The do the occasional 'offer' too where you're able to list for free.
ISTR the last time I was selling stuff on there they had a policy where you could list for free, but only paid any fees if the item sold, any subsequent relistings were also free until the point of sale.
They're a shower of bastards if they've changed that now.