Buying items not in the book

This will be my first time DMing a Starfinder Society game for my friends. One of them asked me what the rule is for buying something (in his case a bag of marbles) that wasn't listed in the book. I pointed him to the Additional Resources and we're both scouring it looking for marbles/ball bearings/similar item.

Is there DM discretion to let Society players buy inconsequential, non-sanctioned items?

Of course, there’s a vast array of technological devices available in most settlements—well beyond the number that could possibly be presented in any real-world book. In general, any minor piece of equipment with a real-world equivalent (alarm clock, camera, digital keys for vehicles you own, timer, watch, and so on) can be purchased with GM approval, costs 5 credits and has light bulk.

My -701 purchased Spray Paint using that logic, and uses it to block security cameras ^_^

If he wants the marbles to be cool or to play a game with them thats perfectly 110% legit.

If he wants to use them as a 1 square grease spell to trip everything thats the sort of thing you need to keep an eye on.

If that happened to be the case, seems like the marbles would be perfect for a dirty trick.