Regarding cash, here's a price per/subscriber comparison of the major marketing automation platforms: https://dripsherpa.com/how-much-does-drip-cost-compared-to-mailchimp-aweber-active-campaign-infusionsoft-ontraport-marketo-hubspot-and-mad-mimi/

I'm a fan of Drip for your use case because it's easy to use and hits a great price point.

But the larger question I'd urge you to consider is this: What one place in your sales funnel would implementing marketing automation reduce friction or increase conversions?

I think it's easy to think of marketing automation as a magic bullet, while in reality it is a powerful toolkit that requires an investment of expertise and effort to get the most out of it.

If you start *small* with marketing automation you're more likely to have a successful first project that provides the monetary and emotional ROI necessary to move onto a bigger project.