Squog, I was kind of playing around with the idea of starting to hunt for comets and supernovae . Amateurs discover new things all the time (kind of surprises me with the resources and technology available to the pro's these days). Hmmm.. Comet SimHQ has a different ring to it

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JS, like with many hobbies, you can sink a little bit of cash into it, or a boatload. It is a slippery slope though as if you get hooked you will find yourself justifying the cost of lots of upgrades and equipment. There is a whole cottage industry out there that caters to the 'gearheads' in this hobby. My gear is almost all second hand, which saved a lot. I started out with a factory refurbished 3in Meade ETX70 scope and a $100 webcam. This setup cost me $250 total (I already had a laptop PC). It was good enough to image the Cassini division in Saturn's rings and Jupiter's Great Red Spot.
My present gear is more expensive but not terribly so when you consider other hobbies. For example, if you decided to learn to fly right now you would be looking at something like $5000 for the PPL. You can get a very nice astro-imaging setup for that kind of money (and without the recurring expenses of aircraft rental, insurance etc etc). Flying was my expensive hobby for a while, so compared to that Astro-imaging is relatively cheap.
A couple of years ago I wrote an article for the 'Cloudy Nights' website that described my first two years in the hobby. My images have improved a lot since I wrote the article, but it does illustrate what you can expect to achieve when just starting out..
Astro-Imaging: Climbing the Learning Curve.