The cost in money will vary depending on how much scrouging you do.
Some EVs have been done as cheaply as $500 and others have spent well over $30,000.
It depends on your driving requirements, the $500 EV won't perform or go as far as the $30,000, but the $500 dollar EV worked for them.
If you bought all of your parts new, then there is that added cost.
Cost in Time
The cost in time will vary depending on how you do your conversion.......
It will usually take most 8-12 months for people to convert their vehicles.
It all depends on how much time you can dedicate to working on the car and how long it takes to wait on parts to get finished like a motor mount plate, parts, tools, etc.