I've been price tracking watching the Bocce balls sets on Amazon. For decent play, you want resin, not composite bocce balls (heavier, like a pool table ball). These typically run $25-$35 for 100mm size. For example, the Amazon Basics version [amazon.com]
Franklin's Advanced level model gets decent reviews, except for the carry bag. They've consistently been over $30 for the past year, bouncing down once to $25 last month. Now they are essentially half price at $14.35. It's presently on backorder, though, but orders can be placed.