I would say that it is definitely worthwhile. A good point to start is consulting Robin Leadbeater's excellent web-page: Simple Low Resolution Spectroscopy of Bright Stars Using a Digital SLR Camera (http://www.threehill...troscopy_11.htm) and Robin might chime in here and take over.
Are there free software options?
Because their software is $109 and the Annual Update is $24.
V-Spec by Valérie Desnoux would be an alternative to R-Spec: http://www.astrosurf.com/vdesnoux/
However, be aware, this program, while free, requires a steep learning curve and is not the best program for beginners. I bought a license for R-Spec and within a few minutes I was up and running with it.
(Both programs are described in: Using Commercial Amateur Astronomical Spectrographs by Jeffrey Hopkins - a book which I can recommend for beginners)
Or do I also need major magnification?
I do have an SCT telescope but I just thought I'd have the Spectroscopy independent from it.
I'd get it its own telescope if the DSLR is just a silly option.
Using the Star Analyser in the converging beam of a SCT in a filter wheel gives you more light, a higher sensitivity and flexibility. So it's not necessary to get its own telescope (that's one of the reasons why the Hubble Space Telescope is equipped with a grism. See also Robin's web-page for more information on the Star Analyser in the converging beam setup:
And finally a warning: You can get easily addicted to spectroscopy ....
Edited by mwr, 07 August 2020 - 11:26 AM.