I have 35mm 760mm wide bars on 2 of my bikes. Only one that doesn't is my SS. My plus bike has a rigid fork and I haven't noticed any issues with stiffness. I think they tend to use less material to make them lighter than their 31.8 equivalents as far as width goes. But yes, most of that is personal preference so your results may vary.
Even if paying the $10 shpiiing fee (orders over $100 ship free though) the total is still at least $30 cheaper than any US retailer. I've had good luck finding Easton bars on Amazon in the $100 to $110 price range but nothing ever below $70.