Check out Ishibashi's Fender Japan site,
http://www.ishibashi.co.jp/webshop/guitar/fender-j/st-index.htm
All their cheaper models used basswood. I can't find any direct info on these, but basswood is more easily available in East Asia, say, China, Korea, etc. While Alder are mainly from North American countries, hence the price difference. If you checked, most Japanese companies, such as Ibanez and Fernandes, have all switched to using basswood for their lower range products, whereas alder is normally reserved for higher ranged models..
Anyway, basswood is easier to finish (paint) too. Because they are close-grained, they do not need much primer and effort to make glossy finishing. Whereas alder is slightly wider grain, to make a gloss finish, more primer and sanding have to be done to make the end product shine.
From the manufacturer's point of view, to put out a cheaper model guitar, they have to cut corners, hence, the use of basswood, satin finish on the neck etc..
Short scale neck means the neck length is shorter. The radius, no. of frets, nut width are all the same. Its just that the difference between each frets are shorter and compared to a normal scale one. Hence, short scale guitars are often designated as "student" models. Ie. Fender Duosonic, Bronco etc..
In simpler terms, the shorter the scale length, the closer the frets are to each other.. :twisted: