How much should I expect to spend on "cheap" builds?

Probably a really dumb question but I'm a little confused about cheap vs expensive builds. Every time I see a build listed as cheap or budget I check the gear and what they recommend ends up being usually 3-4EX, which seems expensive to me since I always feel like I have to grind forever to get even 1EX. Could someone give me an example range of how many EX I should expect to spend from a cheap build up to a really expensive build?