He's been online after this thread has been posted, so pretty much confirms that he is indeed a con artist.

You should never send first with any method other than the ones that you know are reversible. Otherwise, simply go through an escrow. 100 GBP is a pretty high amount at stake here. The reason that he sent you a payment link instead of email for the skrill payment is probably avoid any future chargebacks since you can't prove who you were dealing with or what goods you were buying.

He's merely a member on the forum, so his account is definitely worth less than the amount he scammed. Take this as a lesson - don't believe in people, unless they use escrow. Also Amazon GCs are dangerous to work with even with escrow, as they themselves often are fraudulently obtained.