It doesn't take anything special in the way of a telescope to do astronomy. If you're interested in comets, and possibly hunting for them yourself, check out Don's website at http://www.thecomethunter.com/. There's a whole bunch of info there, including one of Don's books, "A Decade of Comets", and a spreadsheet for comet-hunters.
Don's telescopes are very simple, but very effective. What he accomplishes using them is a result of planning and skill, not fancy expensive equipment. Check out his site for yourself, there's a lot there on many aspects of amateur astronomy.