Have you ever thought that, while there is a bit more complexity and sometimes difficulty in repairing them, that those that have them, like them so well that they do not often put them up for sale?
Here is some info on mine (with a picture & a YouTube video of someone else's.
Technics SL-M3:
Type: fully automatic
Drive method: direct drive
Motor: brushless DC motor
Drive control method: quartz phase locked control
Platter: 325mm, 2.5kg, aluminum die-cast
Pitch control: +-6% range
Speeds: 33 and 45rpm
Wow and flutter: 0.022% WRMS
Rumble: -82dB
Tonearm: dynamically-balanced linear tracking
Effective length: 238mm
Effective mass: 13g (including cartridge)
Cartridge: moving magnet
Replacement stylus: EPS-33ES
Dimensions: 526 x 205 x 425mm
Weight: 15kg
Here is a picture of my Technics SL-M3 (the only turntable in my house [my other TT is a DUAL 1229 which is at my mother's house]).
View attachment 466623
Mine is also complicated by using a T4P (9 certain spec of P-Mount cartridge) for which I have a couple of NOS Technics P33, several NOS variations of the SHURE P-Mounts (V15 LT, V 15 V-P & a few others), and a GRADO GOLD GOLD 3.
Repairing TT's these can be an issue, also:
But I do not know anyone that currently has a working higher end linear tracking TT that would be willing to sell it.
Low popularity at the time led to scarcity and those that have them, tend to keep them, because when working properly, they are damn good.
EJ3