back in 2006 xmas bought the family a fridge for $15,000 RD, roughly $500 USD give or take. you can definately get cheaper. keep in mind this was purchased brand new from an appliance store in San Cristobal.
ive seen plenty of used refridgerators sell for under $10,000RD [$300 USD] just about anywhere [small cities, capital, rural]. i dont know any places in santiago but i am sure you can find plenty there!