My son is at a D3. He didn't have to pay for the team uniform, but he also doesn't get to keep it. Since this is only his second season, I don't know how many years they keep the uniforms.
Some of his practice gear he received free of charge. His first year, he had to buy some items. I don't remember what the cost of the mandatory items were, but we spent close to $1000. However, that included the swag for me, my husband and our two other children, plus he bought extra items. This year, our cost was less than $100.
We have a team parent and they ask for money for lunches for the guys on game day. It was $250 this year. We pay a fee for his spring break trip. During the regular season, everyone traveled with the team. They did not have a "travel" team. The team advanced to the D3 College World Series this past spring. We did not have to pay anything additional for the travel and they took everyone who wanted to go, even the guys who were not on the travel roster.