I'd like to know but you'd have to adjust for other factors to get a definitive answer for which is cheaper to run, for example, a condenser dehumidifier will pump out a bit of heat, and a heat pump drier will (I think) take a bit of the heat from the surrounding air.
Our heat pump drier definitely warms the room it’s in and apparently costs ~23p per load based on 160 mixed cycles using 308kwh (which is the EU standard test thing).
I haven’t noticed any particular impact on our electricity bills whether we use it loads or not...
Which uses more electricity - running a drying cycle or hanging up damp washing indoors and using a dehumidifier?