He was doing not a lot in NSW CUP. Most watching would of had 2nd thoughts and not attract offers in excess of 400k never even playing NRL.
BA cost us Blaize Talagi and it's as simple as that.
This is his stats (before debuting) from his first 2 games in NSW cup at 19 in a new position at fullback. It's also his first ever footy in open aged footy:
1 - 19 runs 151 m 66 pc 2 TA 2 LBA 3 TB
2 - 17 runs 153 m 60 pc 3 TB
Big PC metres for a 19 year old back!
If a recruitment officer saw those stats / watched him play (which is all of them and their fancy video programs), it wouId just re-enforce what they already knew about Talagi, he is a powerful runner of the ball with playing making skills. And after doing it against kids his own age, he could easily do it against men.
Wouldn't have made any difference if he had debuted or not. If he stayed in NSW cup, he would have just continued to post good stats like above, re-enforce what every recruitment offer knew about him and any club looking for a half would thrown a big deal at him.
BTW not playing NRL did not stop the raiders by signing our own Sanders on a big 6 figure / 3 year deal (even before he played NSW cup). Or the big offer Knights offered Pezet or the big offer Drown got from the Knights! Plenty of examples of players that can play halves getting big offers before barely playing NRL.