there are generally 2 types of st70's. the classic ones are the earlier production. these are tube-rectified and with cloth-covered transformer wires. these are the sought after ones.
stock st70's (orig parts, good tubes) and plays well, with no rust range from p20-30t depending on condition and brand of tubes.
expect to pay p3-5k more if factory wired.
for fully restored units, expect to pay p35-50k depending on parts and tubes used.