Learn English – the difference between now and yet

There are various parts to this; I'm focusing on only the overall meaning of each (as opposed to, say, the nuance introduced by "just"). So, I can construct a scenario where Example 1 is perfectly correct, but it means something different from Example 2. I'll use a slightly different example to illustrate:

Example 3

My friend: I am going to draw various things. For each drawing, I'll tell you I have done it and I want you to draw the same and then tell me when you're done.

Me: OK

My friend: [scribble scribble scribble] I have drawn a set of keys sitting on a desk

Me: [scribble scribble scribble] OK, I have just drawn the same thing

My friend: [continues onto next drawing]

Example 4

My friend: [Out of the blue holds up a picture he's drawn] Look! I have drawn a set of keys sitting on a desk

Me: Holy crap, that's amazing! I just drew the same thing!

My friend: [stares at my drawing, then me, then back at my drawing, terrified, as if I might be some kind of witch]

It wouldn't be too hard to morph that into something to do with thoughts rather than drawings -- maybe a scenario with a stage magician/mind-reader asking people to think of things and then tell him when they've done it. Doxastic involuntarism aside, I think the comparison works.

But, ignoring that contrived example, with the meaning implied in your context I would not use Example 1. Example 2 is better/idiomatic.

"Expence" is an obsolete spelling of "expense" (like whiche and laste and many, many others) and should not be used. You might see "expence" in archaic documents, but in modern documents it's simply a spelling mistake.

Example from "The Expence of University Education Reduced: In a Letter to A. B. Fellow E.C." (1733)

The Expence requiſite to Education has Limits, and may be known to a certainty within a trifle. The Expence occaſion'd by Idleneſs, or Humour, or Vanity, or Luxury, or Affected Hoſpitality is Infinite, or, at leaſt, hath no other.

Note the long s (ſ) which is pronounced like "s", as well as the capitalization of certain nouns, both of which no longer appear in modern English.