Hi! The difference in price ranges between red and white wines can be explained by many factors. I would start considering the wines aged in wood, for example. These usually are richer wines (a bit heavier or more intense in their composition, yet finer), they are more expensive because of this and they are mostly wines from red grapes. Therefore, the "gap in quality between low and high priced red wines vs white wines" is similar in my opinion but possibly a bit more stretched for the red wines because there are more aged red wines which usually have higher prices. So, trying to give a usuful answer... if we agree that beyond a certain price level it is easier to find better wines, that livel in absolute terms is set slightly lower for whites that for reds, for example above $45.00 it is easier to find the value in whites than it is to find it in reds.
I don't know in which part of California you are from, but this whould be my quick recommendation:
> for the red, Zinfandel of Balletto vineyards in Santa Rosa has a great quality/price ratio. The 2017 is very good, if you can find it.
> for the white I'd like to give you an alternative for the Chardonnay, which can be an Arneis from Piedmont, Italy. There is one importer called Peloton wine imports (755 Skyway Ct, Napa, CA 94558, United States). I cannot reach their website now but you would call them maybe (+1 707-226-5893), and ask if they still have Roero Arneis of Valdinera winery, Piedmont (or if they can suggest a good alternative in comparison to that).