I drive 60-80 miles per day on average, and I came from a 2014 Prius - my running cost for that car from new purchase to time of sale, including fuel and all maintenance (tires, oil changes I did myself) was $0.07 per mile. At this time, my Model 3 (using Georgia Power Tier 3 rates of $0.12/kWh ($0.09 + taxes/fees/etc)) is costing between $0.03 - $0.04 per mile - keep in mind this is just electricity cost since I've only had the car 6 months / 11,000 miles. Approximately half of the Prius cost, but that number is bound to rise once I have to purchase tires.
I am a believer of the Prius - this car is the cheapest hybrid to operate, and the base price of $25,500 is hard to beat (I purchased mine for $21,500 + tax/tag/title). Overall 5year cost of ownership (excluding depreciation), a base model Prius has a Model 3 SR+ beat by a long shot due to the higher up-front cost of the SR+. The roughly $14,000 base price difference between the two cars will have you driving the Prius an equivalent of 200,000 miles. If you priced the top trim Prius ($34,400) VS a Model 3 SR+ ($39,990), you reduce the mileage the Prius will have you driving to around 80,000 miles.
But this is not a fair comparison. A Model 3 SR+ with basic Autopilot has so much more to offer in terms of creature comforts, tech, and performance - even compared to a top trim Prius. If you haven't experienced even basic Autopilot in long interstate drives, it is a priceless, game-changing experience.
If you're wanting the cheapest possible TCO - a base model Prius is your best bet in my opinion instead of a Model 3.
If you're considering a luxury sedan (BMW 3-series, Audi A4, Mercedes C-class) - the Model 3 is a no brainer with base/mid trim luxury sedans in the $40,000 - 50,000 price range.
Compared to a CPO Camry Hybrid, you'll probably come out ahead since a CPO car has already taken a depreciation hit. The car would have to be in the low to mid $30k range to start coming out even @ 200,000 miles of driving for both cars.