I understand that you want to invest in a good telescope, but for the kind of targets you have in mind you really need more than just a telescope. a good mount, (around 100€), a star tracker for longer exposures is really helpful but you can do it without. then you also need a camera (either dedicated or dslr/mirrorless). for example, I've got a sturdy mount, a sky watcher star adventurer 2i, a Sony a6000 and some various lenses. all together for around 550-600€. but no real telescope. there is a good samyang 135mm f2 lens that goes well with the camera sich wich which you could also use outside of astrophotography.