What about the
Supatrac Blackbird? Mikey posted two needle drops with the same turntable (Oswalds Mill K3) and cartridge (Lyra Atlas SL) with the Blackbird and the SAT CF1-12 ($67k) but didn't say which was which. It was close but the majority preferred the Blackbird.
It is available in different lengths and has an effective mass of only 10g (9" version) which you can load up with adapters if you need higher. Based on the GBP pricing the 10.5" comes in at a whisker over $5K.
You may not like the looks but IMO (and several well known journalists FWIW) it is the biggest step forward in tonearm design since the gimbal bearing. It is a unipivot, but a
horizontal one, so it does not suffer the "wobbliness" of a traditional unipivot. The closest thing in the market is probably the Kuzma Four Point. If the journos are to be believed you won't get anywhere close for the money.