This decision usually has a lot of variables for me. Speaking in general terms, if he’s “replacement level”, or just a bit above, I pass. If the guy does something well that might be useful to the team a few years down the road, I’ll consider it. I think I probably value scholarship resources a bit less than average, in part because I run press/zone combo defenses that benefit from lineup flexibility.
Having an extra scholarship is no guarantee that you’ll have a better time replacing it next year; and depending on what else is happening on the team, a guy who is better than a walkon for a couple years, and then a useful guy off the bench with upperclassman IQ can improve your chances to win games. I had 6 scholarships with OK St last year, and still swung and missed on 3 frontcourt players (and had a backup option poached late), and so I’m starting the center project I signed in this situation 2 seasons ago, as a redshirt freshman. Crazy things happen.