Executive/Entrepreneur with many bruises that have taught me valuable lessons, technology, marketing, strategy and leadership. Would be glad to help people with their challenges and at the same time help a cause that is dear to my heart.
This is one area I would not cut-corners. If you are serious about this business then DIY is definitely not the way to go. It should not cost you a lot to get a Subscription Agreement drafted. You can always look at the contract of some of the successful SaaS companies, by asking one of your Sales friends, who might be working there but use that as a reference so when you work with your lawyer you know if your agreement is comprehensive.
Frankly without customers it would be a challenge to position the IP for a sale. With the barrier to entry being low in building the base technology, you have to show that there is something compelling you have built and customers really need this solution (even if they are not paying).
(Admittedly) In hindsight I can tell you this - don't build anything till you have lined up customers who are ready to pay. This is true even if you are building a freemium product.
Unless the technology you have built is remarkable and might find a place in some other company and given that the amount is relatively small, I would attribute it to cost of lesson learnt and move forward.