This is a very applied question so I hope it's the correct adress here for it:
I'm running a small entertaining business for virtual reality experiences. Investment was about 120 k. I now build it all up and just opened a week ago. Money left is 25 k. There are two major things I would like to buy, one costs 6 k, the other 18 k (both software licences). At the moment, without any income, I can survive about one year. That's why I probably will skip the expensive one of both licences. On the other hand it is a high award winning experience and also advertised by very famous people in our nation. That's why I'm not skipping it at all in my head. The other one I guess it could fit to my finances. But anyhow, since VR is probably requested way more in winter time than in summer time I'm not sure how much profit I'll gain and if it is smart to invest into one of both.
Is there thumb of rule or even any academic method how to figure out if an investment promises to be a good decision? I'm aware that it is probably rather difficult but I'm a technician and I'm used to research anything at different methods. Hence, I believe there must be some tools to use for business purposes?