Turntable mat for Sony PS-x6

The platter on the PS-X6 rings like a bell. The arm height is not too adjustable which may limit what the options are. To damp the platter you may want to try a 2mm brass mat from doukmall then add a thin rubber mat on top of it. The brass will damp the aluminum platter very well. Getting both should be doable for under your budget. 

I use a rubber mat under a gunmetal mat.   Best combo so far

Thanks for all the suggestions. I decided to splurge and bought a SPEC+Analog Disc Stabilizer. I've also just bought a fully cleaned and refurbished Sony PS-x50 turntable that does have an adjustable arm height. I've read really good reviews about the SPEC+. If I don't like it I can return it.