Hi, If you do everything yourself you are looking at about $35k just in parts. I dont think your budget is realistic, with all due respect.
Every one wants the 400 mile range at 75 MPH in their Mini, OK where are you going to put all the cells ? all in the back seat area and next to you where the passenger seat was ? still not enough room, OK I have the solution . put the rest in a trailer. that will work NOT !!!!. people some how loose all common sense when they want to build a EV. small , every time, but they forget about battery space, and what will all that extra weight do to the suspension , steering and brakes.
You have to find a medium to work with, then they say, OK Ill get a Jeep Cherokee, now you have the room and your carrying more weight . your not going to get that long range and at that speed no matter what you do or who tells you different .
Manufactures have spent a billion dollars to research this and they still are putting out crap that is always barking down.
I think that Tesla ism the only one that has done well so far. Now there a full recall on the news to remove all the self driving crap
as for me I dont own a EV or do I want one. I do it as a business and its been very good, this may be my last year in it. age and health are working their magic on me , sell off everything , move back to Florida and drown shrimp