I was going to add a link to this 325 manual for $28k : trademelink
Then I got a little carried away, current trademe asking prices for e30's from March 2021 below. Obviously there are other factors which influence price, condition, location, trim/accessory options etc.
1990 320i manual, 4dr, 300km (few small issues) $4,000
1990 318i manual , 4dr, 151km, (dereg) $4,300
1988 320i Auto, 4dr, 170km $5,200
1990 320i manual , 4dr, 233km $5,500
1990 320i manual , 4dr, 238km $5,500
1990 318i manual , 4dr, 255km $6,000
1986 318i Auto, 4dr, 142km $6,500
1989 320i manual, 4dr, 160km $7,000
1985 320i manual, 4dr, 285km,$7,000
1991 318i auto, 4dr, 128km, $8,500
1990 320i auto, 4dr, 206km $8,500
1989 320i manual, 4dr, 227km $8,500
1988 320i auto, 2dr, 210km $9,500
1988 316i manual, 2dr, 213km $9,700
1990 318i manual, 4dr 224km $9,950
1985 323i manual, 4dr 330km $11,999
1987 325e manual, 2dr $12,000
1988 318i, 2dr, 106km $13,500
1988 318, 4dr, 180km, $13,000
1988 320i manual, 2dr, $13,000
1988 320i manual, 2dr, 100km $13,500
1984 320i manual, 2dr, 177km $17,500
1990 320iSE manual, 4dr, 244km $18,000
1985 323i auto, vert, 132km, $18,500
1987 325i manual, 4dr, 162km $18,900
1988 320i manual, 2dr, 250km, $19,500
1989 325i manual, 4dr, 99km, $28,000