A few days ago I showed the schematic for my WISPY RX. The photo shows the actual 10m WISPY RX.
With a couple of low cost GQRP 7030kHz crystals in parallel this could probably allow a very low cost 20m FT8 RX to be made using the same idea and pulling the crystals upwards.
If you have a source of low cost 7040kHz crystals, just one will probably allow you to get to half 14.074MHz. A 14.074MHz simple DSB based FT8 RX would be a fun winter project, guaranteed to spot lots of DX every day.
Just think - for the cost of a couple of coffees out (those were the days!) and you have a low cost way of spotting DX from across the world.
Come to think of it, a full 20m FT8 transceiver could be made for the price of a bag of fish and chips! Surely someone is up for the challenge.