Can a material other than glass be used for making telescope mirrors? Although I do know of a few instances where professional or observatory mirrors have been made by alternate materials, it was primarily for targeting specific nuances, like weight reduction and low thermal expansion etc. 

I was more keen on finding a material whose primary unique selling point is low cost ;P , keeping in mind a budding amateur astronomer.
Front-surface glass mirrors weren't developed until the 1850s.
Before that, the most common material was speculum metal, a high-tin bronze.
Notable examples include Isaac Newton's 1668 prototype and William Herschel's late 18th century telescopes.
Since speculum metal tarnished easily, it was common to have a spare mirror to continue observations while the other was being reconditioned.
Reflectivity and thermal characteristics were not great either.