Season 1 had 100 shows, yes. #S-100 ends with no prizes previewed for next week and Jim saying "We thank you for joining us on
Sale of the Century." (as their renewal was still up in the air at the time), while #S-101 opens with Jim welcoming viewers to a new season of
Sale.
Aside from that, Season 2 evidently aired some repeats at Christmas/New Year's, given Jim's comment on #S-166 (the first show with a 1986 copyright date):
Welcome to Sale of the Century, delighted to have you with us, and I understand some new stations have joined the Sale of the Century family. Happy to have you aboard, you'll get the idea how we play our game very quickly.
...Which would make more sense if said at midseason. Further, per
this recollection on JBoard by an audience member who saw Rocky Brown's last two shows (166-167), those were taped 12/20/85 (he previously mentioned it
on ATGS in 1999), and I don't think they would've had a 1986 copyright date if they weren't scheduled to air in January.
As such, it's believed the show took three weeks of repeats just before midseason, which would end the run at May 30 with repeats through September 12. In addition to this, Greg Brobeck's collection lists Lisa Munoz/Ryan/Ann as having aired February 24, 1986 (it's an original broadcast with commercials), which should be #S-201 if all my above assumptions about repeats are correct.