Lots of factors to consider like outdoor temps, size of fridge, condition of batteries, etc. Last year I replaced a failing Dometic 8 cu. ft. RV fridge with a $300 open box Whirlpool 11.8 residential connected to a $100 2000W inverter running off of (2) 12V batteries. It's ready to pack in 1 hour, lots more space inside, & it lasts over 1 day on a hot beach with just (2) 12V batteries. I found WEN Yamaha 2000 clones for $375. One charges the batteries in 2-3 hours & two will provide 30A for the A/C if the temps get too miserable...
2011 RAM 2500 ST Crew Cab 5.7 Hemi ($14K in '13)
2011 Primetime 3150BHD Touring Edition ($20K in '14)
Days camped in 2018-25