"Vintage Guitar Price Value For 2009 :
1969 > $4700 to $5500 ( Goldtop )
1970 > $4000 to $5000 ( Goldtop )
1971 - 1975 > $3500 to $4300 ( Goldtop )
1971 - 1975 > $2500 to $3000 ( various colors )
1976 - 1985 > $2000 to $2700 ( various colors )
1978 - 1982 > $1500 to $2100 ( pro-deluxe with 2 p-90 pickups )
gibson les paul deluxe price guide1969 - Avg Upward Trend Of 15% a Year since 2000
1970 - 1985 Avg Upward Trend Of 11% a Year since 2000
( in 1975 and 1977 red and blue sparkle finishes are estimated at $3900 to $4500 , they made them only in those years and are very rare , hard to find . )"
source:
http://vintage-guitars.blogspot.com/2006/01/gibson-les-paul-deluxe.html
Though obviously you'll get nothing like that for an old beater, and certainly not in SA. Weirdly this blog posting claims that between 1970 and 1985 when they were discontinued, features remained largely unchanged. The Gibson Catalogue says very different. In 1983 they dropped the maple neck, pancake body, and larger headstock design - and went for more vintage spec. Same as the Standard, they say, except for the electronics.