This personalized baseball could be a great ring bearer gift or even a groomsmen gift (though I tend to think the little guys will love it more).
The one pictured above is from Etsy seller UrbanFarmhouseTampa for $16.
Other Etsy sellers I found selling something similar are below. You could even add a bat to make it a complete custom gift set.
Via Etsy seller EngraveMyMemories, $9.95
Via Etsy seller EngravingsOnDemand, $14.99