TBH I think different people will take it different ways
some people will think it show commitment, because wven though you cant afford the software you still stuck at it
others may take it the other way and think you dont have the commitment to shell out for the software
this month 3D world did a feature on what to/not to do in a showreel. they didnt mention either way.
I would suggest asking recruiters what they think
although as long as the work is good it wont matter if its watermarked