If you are like most if us, you will talk yourself into the 600$ scope and wish you would have bought the better one later and eventually end up selling yours and upgrading. The best equipment you can afford is sorry enough. Go for it man. Buy once cry once.
I always adhere to the buy the best you can, and just buy it once.. I broke my own rules last year, and bought a Nikon Prostaff, when I should have bought better glass. It currently serves as an excellent paperweight. I'm currently in the process of looking for glass that I will actually use..
Anyone wanna buy a nearly never used Nikon Prostaff.