I'm not sure id call diesel
I'm not sure id call diesel artificially expensive. Its a global market and it's heavily disrupted at the moment. That said, 7c a kwh is amazingly cheap. Mine is slightly below national average and its 10-11c per kwh. Figure trucking companies will get bulk discounts or off-peak discounts and you still have to add some infrastructure markup (even if the semi only charges at home-base at raw elec prices you still need to figure the charging infrastructure installation).
All that said, a model 3 or model Y is a massive savings over a similarly equipped gas car right now. If you compare them to their market equivalents they sit at nearly the same prices (50-65k$) and cost vastly less per mile to drive. If your in the market for a 50k$ luxury sedan or a 60-65k$ SUV then buying a gas car will cost you 25-35k$ extra over the life of the car (150-200k miles) just for fuel!!
The charging infrastructure for the semis should be fairly straightforward to setup because they tend to have specific routes. Putting superchargers along those routes at specific intervals will easily service the trucking industry (we wont need stations on every block like we have with gas cars at the moment).
I think our biggest problem for the next decade will be lowering the price on the batteries and making enough of them quickly enough. Even with passenger cars we are talking about 1 ton of batteries for every 2 cars. Just replacing 10% of new cars sold in the USA will require a million pounds of batteries every year. Replacing 10% of new cars with EVs will require 10 times as many as tesla is making per year currently (if all those sold were teslas).
I dont think ill likely own another gas vehicle at this point. Most of my yard equipment is electric now and its just better. I expect our next vehicle to be a model 3 or Y (unless another manufacturer really pulls a rabbit out of a hat in the next 12-24 months).