I haven't renovated a kitchen myself, but my home is about the same value as yours, and I think I'd be willing to put about $50K into a redo. I think this would update the kitchen to make it more competitive from a resale perspective without pricing us out of comparable homes in our neighborhood.
Like anything else we buy, you have to consider how you will use it. If you're a gourmet cook and need a pastry station, potfiller, warming trays, super duper range hood, and Viking appliances, you're going to want to spend more. If you're an average cook, you probably wouldn't want to invest in these upgrades.
The same consideration must be taken if you're looking for high design finishes or are just happy to have the room clean and modern, and doesn't have to be done again for another decade or two. For myself, granite is granite so I don't need the $200/foot variety and can happily choose something from the offerings that are $50 a foot. It helps if I never set foot in the pricier area so don't start to covet the expensive options. Others, though, might feel like they skimped every time they had to look at the counters.
There was a thread here on Ikea cabinets recently and it spurred me to investigate the reviews. I was shocked at how favorably many designers look at them.
I know that for my kitchen - which is old and outdated with dark wood cabinets and (gasp!) Formica counter-tops - I'd love to do a total reno. However, if it was going to cost upwards of $70K, I'd live with it for a few more years. Of course, then I'd redo it in order to sell it and someone else would enjoy my new kitchen while I suffered with the old one, but now we're exposing some of my own issues, so I'll leave....