Well those forums believe a starter with corn sugar is bad. But two ideas did pop up, one to borrow some of the DME that I'd be brewing with and add everything when I pitch the yeast, instead of cold crashing and decanting, or to use Malto Goya which apparently is available at the supermarket. Any thoughts on these.
Assuming you are brewing a normal gravity maltose based beer, I'd go with using a maltose based starter so you get your yeast accustomed to maltose and not dextrose. Using dextrose as a starter may get you a lower attenuation. (I've never used anything other than DME for a starter.)
In a pinch, I'd lean towards your first idea, using the DME from your recipe and dumping the whole starter when pitching. Don't know about Malto Goya, but if it's maltose based, it sounds like a decent alternative.
Corn Sugar is Dextrose, Table Sugar is Sucrose. Both are like drinking Red Bull to yeast. Maltose, which is sugar from Malt, is much more complex and harder for the yeast to break down. If all they have are easy sugars while growing, thats all they will eat. Sorta like my kid.
I keep a tub of DME around just for starters. I heat up some water in my flask, dump in a couple scoops of DME, add the stirbar and some Servomyces (yeast nutrient), shake the flash, then boil. Once it's done, it goes right into an ice bath with tin foil on top. Once it is cooled, in go the yeast. I then plop it on a stirplate for 2-3 days. Decant the night before brewing.
I use ultra light DME so that any of the spent wort in the starter imparts a little flavor as possible.
The point of the yeast starter is to build your population and to invigorate them to an active state. If you used priming sugar, that would invigorate them but I am fairly certain you wouldn't get a decent population growth. That would also ferment out really dry, which might have an adverse effect on your yeast. Remember malt extract contains very essential nutrients like calcium, magnesium, FAN, etc., that was present in the wort before it was converted to extract. I don't think you'll find all those nutrients/minerals present in priming sugar.