Since it's pretax you save possibly a quarter of what you actually would pay in taxes. So, for instance if you put $100 away for retirement it actually only costs you $75, not the $100. When you add in an employer match of 3% you're actually talking about being able to retire on 4%. It's a no brainer!
Since you're only talking about 4%, max out your contribution limit into a non-employer sponsored plan where you get an additional tax deduction like a traditional IRA. This will help protect you against life's unexpected retirement challenges.