I would start with some growth hacks to increase your sales without raising your costs that much.

1. Social media - provide valuable content related to your SAAS and the industry it targets. Build traction by showing case studies, customer reviews, how customers use your product and how it saves them time & their sanity.

2. Referrals - if you have happy customers who love your product you could create and easy referral program offering your happy customers an incentive for sharing your product. Make this very easy like 1-2 clicks. All the biggest SAAS companies have used this tactic to scale their users rapidly.

3. Create Content - Create valuable content on your website that will laser target your client base in the search engines for the problems they have, and how you can solve them. Along the same lines of the social media content creation... Case studies, how users use your product, videos, reviews, tips & tricks, etc.

I would set aside at least 30 minutes per day and focus on this. Ideally more time will increase sales. But the key is consistency.

I have lots of other ideas how to help here so if you need my help along the way Im just one call away.