I got my Kerrn (German) v calipers for only $12 from a 'lelong' shop in Chinatown. The also have a dial type that's probably lots easier to read, only problem is it's solely in metric, whereas the Kerrn is both metric and imperial.
Sorry, I don't know how to describe excatly where the shop is, but it's the row of shops opposite the last time 'Pieces' closer to Chinatown Plaza side. The lelong shop quite large and also got camping equip/knives etc towards the inside of the shop.
Sorry couldn't give you a better description of where the shop.
Alternatively, if you're looking for a cheap digital one, try Harbour Freight in the US. They have a website. Do a search.