There are different kits, and I've had good experiences with them, but I've never made a white wine kit. In the $50 range, the Winexpert Vintner's Reserve kits are available. To my taste, I could guess that these are equivalent to a maybe $8 bottle of wine as far as quality. I've done a couple of them, and been very happy. I have a shiraz right now in secondary, and we've been drinking a valpollicella for a while. I'm sure their pinot grigio would be a nice kit as well.
There are some higher end kits, like Winexpert's Crushendo series ($160) which even include grape skins. I've never tried them, but I've heard from experienced wine kit makers that these are great. They would be like a $20 bottle or so, to compare to commercial wines.
There are other kits, too, available. There are even kits called "Island Mist" or something like that to make sweetened wine cooler type wines.
All of them make 6 gallons, I believe. I think a Winexpert kit that comes with all of the instructions and ingredients is a great way to start. You can buy a bucket of grape juice from a winemaking shop, but then you have to deal with ph, MLF fermentation, etc. that you don't deal with when you purchase a kit. I would recommend the kit to start, and if you like doing it, then get into grapes and grape juice.
I make a lot more "country" wines than grape wines. My favorite has been rhubarb wine, believe it or not! To me, it tastes very much like a pinot grigio, and turns out to be a white wine.
Let me know if you have any specific questions about wine kits, and I'll try to help!