Is a Fluance RT 85 turntable worthy of a moderately priced moving coil cartridge?

You know the answer already. Go ahead. It just will not perform as well as it could in a better turntable. 

Here you go from a new company trying to break into the market. Le Son SL1 MKII, high output M/C with a boron cantilever and a Micro Line stylus for an entry level price of $499.00. Just ordered mine to install in my headphone system on a Rega RP3. Enjoy the music

No. 

If the table has adjustable VTA then go for it.  However moderately priced MC carts have some real dogs.  I had an Ortofon Quintet Blue and it sounded unrefined and not very good even after burn in.  An Audio-Technica OC9 series or the Hana ML are worthy choices- as long as you have a decent phono preamp. 

The only Fluance turntable that has crossed my path had noticeably loose arm bearings. This might be a peculiarity of the sample and not common to other units.  Check yours for any play in the bearings, and if found, investigate whether it can be adjusted. In my experience chattery bearings are usually not the friend of MC cartridges!  If you want to upgrade from a 2M Blue, consider the AT-OC9XML, Hana ML, or Sumiko Bluepoint 3.  Hana and Sumiko offer high output versions if your preamp is fixed gain at 40dB.