It has been my experience, in the past (before I had my basic battery complete) that if you see something particular that you want, at a fairly reasonable price, you probably should buy it. If you don't, when you come back to buy it........it's gone!!!
The key is to keep looking around, so that you know what is available, elsewhere. Also, check on Gunbroker, to have an idea of what they're selling for. That way, when you see what you want .....you will be able to buy intelligently......on the spot! Oh yeah......keep a credit card or carry cash, so that.....you can act immediately....if not sooner!!! Bob