As with any such questions, the answer is "it depends". If you're lucky, you might get strictly Splunk-related job but it will sooner or later involve non-splunk knowledge and will require you to have some abilities besides Splunk (with Splunk environment administration you should have at least some idea what's going on in your system in general and have some knowledge about general IT and systems administration; with data ingestion it's often useful to know what you're ingesting and understand the data).
On the other hand, you might get a job just using Splunk to get what you want from data that's being accumulated by your organization. So it's important that you know what you need (and that's outside Splunk scope) and how to get it (and here's where Splunk knowledge plays an important part).
Also, as @richgalloway already mentioned - you can get Splunk Free and start using it. It's most interesting if you can find a use for it in your current situation (at work or at home). For example - I track my cars and visualize them on a map with my home Splunk installation, among other things. Nobody says that you need to have several terabytes of raw data daily to start using Splunk. You can start small. You can ingest data exported from your music streaming platform and check your stats (what band you're using the most, which pieces you skip after no more than 30 seconds and so on and so forth). The possibilites are endless.
