Ended up calling in and booked the flight. Verified it afterwards on the Air Transat site afterwards. So it all worked. Was I on hold for a long time? Yes. Was it annoying that the site sucks? Yes. But the phone reps were friendly and helpful. It was a time suck for $99, but hey it’s $99.
If it’s a complicated flight with connections or involves a hotel package, don’t know if pctravel is my first choice. Simple flight to somewhere, I’d do it with them