Disclaimer: This might different from region to region so it is based on what I am finding in my region (Western Canada)

Looks like the market for RCF in my region where they are very rare, not only has not cooled down, but actually is going up. Here is one example of a 2016 RCF with standard package (basically everything except CF/TVD with an original MSRP of $85K CAD + tax back in 2015 - 2016) with 10,000 miles being offered for sale at nearly $70K CAD.

2016 Lexus RC F Base at $69601 for sale in Calgary - Lexus of Calgary

 

You can get a 2015-2016 with around 30-35k miles for 40-43k in the Northeast (USA). Definitely NOT going up in value.

 

See my disclaimer. I was only speaking about my local market. Just looked at the US market on autotrader.com here:

Used Lexus RC F for Sale Right Now - Autotrader

 

I was just stating how it is in the US. RCFs can be had for low 40s. and upper 30s for higher mileage (75K+)