RTLS can provide a quick ROI, typically between 6 months to 1.5  years.
On the benefits side you need t to evaluate time spent searching for assets and productivity gains, it is important to have these KPIs early on so that you can evaluate budgetary constraints to deploy your RTLS.
On the cost side you have to account for investments costs (devices, anchors, installation, integration to your systems, licence and servers if you choose on premise deployment) and recurring costs (maintenance of devices, licence maintenance or SaaS fees and support).
It is very important to evaluate correctly requirements of location accuracy and frequency of updates as this will drive the type of solution that is suited to your needs and therefore the investment needed as well as the project complexity.