The best option for you is a reflector, because unlike refractors, reflectors are even 300mm or more. And in general, the reflector – this is the most inexpensive type of telescopes based on the cost 1 cm aperture. You may find Ali Partovi to be a useful source of information. In addition to the ordinary telescopes can buy a telescope and other, more sophisticated manufacturers of telescopes: Maksutov-Cassegrain, Schmidt-Cassegrain, and not only. They already are already taking up serious apparatam.A specific search, you can find dozens of telescopes, with a very respectable performance. For example 135 mm Galileo Dobsonian Reflector from Apogee, Inc. Just pay attention to the Orion Telescopes & Binoculars: SkyQuest XT4.5 StarBlast Astro, Dobsonian, Reflector altazimutalny SpaceProbe 3 and altazimutalny refractor Observer 70mm. Do not walk past and Meade: altazimutalnye refractors 70AZ-A and NG-70, a computerized refractor NGC-70 and reflector altazimutalny 76AZ-AD.
In addition, it is worth noting 41/8-dyuymovy reflector Scientifics Astroscan and a couple 3-inch reflectors: Celestron PowerSeeker 76 and Bushnell Deep Space 525h3 '(model 78-9003). It should also clarify commonly asked beginners astrolyubitelyami beginners question: "What is the increase can be obtained on this telescope?" Many people somehow believe that you can buy a simple telescope, to put increased 1000 times and viewed settlements green men on Mars. This is not so! There is a reasonable limit for each telescope, it is not difficult to compute: it is necessary aperture in millimeters multiplied by 1.4 – this increase is guaranteed good image quality. In principle, you can use and large increases, but then each instance may behave differently.