There Ain't No Such Thing As a Free Software Package
No question riles me up more. This is a really dangerous mind set. Would you think this way for other types of investments? "That Executive Director candidate seems really great, but who can we get that we don't have to pay?" "That office space seems perfect for us, but $100/month is a lot of money - what can we get for free?" Okay, possibly some nonprofits actually would do this for other things... but it's equally dangerous. Things worth having are worth paying for.
And not paying for them up front almost always means that you're paying in some other way. That free office space is great until it starts raining asbestos on your employees, or you're evicted to make way for a paying tenant. That free software might seem great, but if it doesn't do what you need, or your staff can't use it, or it's full of bugs... then it's useless to you, and it doesn't matter how free it is.
Also, I reject the likelihood that your organization has no money of any sort to devote to software. If you can't raise $300 to purchase a donor database that will help you solicit donations more effectively, you need donors much more than you need a database. I'm not saying that you should spend tens of thousands. I'm saying that you should decide the priority of having effective software and assign a budget to it accordingly. Yes, that might mean you'll have to fund raise for it.
Don't get me wrong. Free stuff is nice. I use some free software myself. But it's a BONUS that it's free. You can't start with that as a requirement and expect to end up in a good place. If a software package will help you save time or money, or earn more money, then it's worth paying for....and if it won't, you shouldn't waste your time with it.