If I make my own telescope, will I save money?
That depends on two things: how large a telescope you’re considering, and how many of the pieces you plan to build versus buy. Given the low prices of today’s commercial telescopes, you will be hard pressed to save money building a 6-inch reflector unless you’re quite resourceful. But a 10-inch scope is expensive enough that you should be able to save some money making your own, especially if you grind and polish your own mirror. With larger instruments it becomes progressively easier to beat the price of an equivalent commercial scope.
If you purchase all the components (mirrors, focuser, mirror cells, etc.), it’s going to cost a good deal more to assemble your telescope than to buy it, as a quick perusal of the advertisements in this magazine will bear out. Almost always, your best chance to save money is by making the telescope’s most important and costly part — the primary mirror. And the sense of accomplishment you’ll get, as the credit-card commercial says, is priceless.
— Gary Seronik