How do you determine how much to spend on speakers

By looking at my checkbook.

I have done it before. At mid end HIFI. Out of all the equipments, the speakers can make the biggest difference. Go and listen as they all sound different! Try to get as full range as possible as oppose to those refined monitors or you will end up addicted only to vocals. Save up next for the best amp to fit power to your speakers. Source doesn't make huge difference until you get into super hi-end. At that time onward, the source becomes the most important and only analogue can fill the bill.

Get the BEST speakers you can even if you can't afford them. And what makes them the BEST?, only you can make that judgement. No one else hears or gives meaning to what your hearing as you do.

As an update. My primary system is now using a Yaqin MC-30L that cost about $600 with my Focal 836v speakers that cost $3,000. I couldn't be more happy with the amplifier or the system. It is more about individual products and not relative price points.

I know little about digital. I guess I can see how having full range speakers hooked up to a mighty HT Denon could impress. However on a vinyl rig, where you want to hear the horsehairs snap on a bow and the tears in the voice of a treble, I would spend the most on the turntable, then amp, then speakers. Most people don't understand that you cannot get back the detail lost at the source. I have heard top flight rigs with baby Wharfedales blow away bottom heavy set-ups.