Hi Mika!
How are you all collecting your donations that get put onto the spreadsheet? I am guessing it is a mix of online and offline?
As far as low cost donor management goes, Little Green Light and Donor Box are two that I hear the most and know are fairly low cost.
Another option that is free would be HubSpot, but you'd want to integrate something to take donations. We always recommend Fundraise Up. The free version of HubSpot doesn't have a TON of features, but it is a good gateway to collecting donor data and logging necessary interactions. Hope this helps :)
------------------------------
Karen Senette
Head of Business Development
Digital Reach Online Solutions
Anchorage AK
------------------------------