Hi,
At work I use a 24" monitor just for ADSM201
Regarding ADSM302, if I had (personally) an ADSM201 I would not make the upgrade (feature wise) but since I want to buy a new one for myself I like to buy the newest thing (of course, not if it has serious issues).
Banggood price is depending on the area you are. In my case the price is about the same as the one found on Aliexpress (Ali price is 295USD but shipping can be made from Germany, therefore no taxes).
I was looking also on ADSM301 for which the price is really lower than ADSM302 but I can't understand why ...