Quality optics will cost more regardless of power, ie a Swarovski 20x will cost more than a Tasco 60x.
I believe my spotter is 20-60x 65mm, and most of the time 60x isn't as clear as 45x etc...
if you really want to use 60x I suggest you get a high quality glass 65mm, or go to 80mm lenses.
Of course get the best you can afford.
IMO if you get a dcent scope say 20-60x65, plan on max usable power around 45x most of the time. If you want more magnification, goto the 80mm and/or high quality glass. 20-60x80mm
Part of me would like to have a big high quality 20-60x80mm and then get a backpack/lightweight something like 30-40x65mm or even smaller.