I saw a 600-power telescope at a local department store. Is that a good deal?

No. The most common “department store” telescopes we see are small (60mm) refractors or cheap reflectors with plastic optics, terrible, dim eyepieces, and a wobbly mount. STAY AWAY FROM DEPARTMENT STORE TELESCOPES! These things tend to frustrate budding amateur astronomers and can turn them off of astronomy really quick.

The three most important things in any great, easy-to-use telescope are: high quality optics, a rock-stable mount, and sufficient aperture (mirror or lens diameter) to see interesting objects. The typical department-store telescope has none of these things. If you are wanting a good beginner telescope FWAS recommends searching for reputable local stores that specialize in selling telescopes, or websites like Orion Telescopes that have a track record of selling quality telescopes to beginners for reasonable prices.