02 won't start

[purist]

Here's the background: 02 Escort would not start intermittently. EAch time afte piddling with the battery cables or starter, it would finally start. Then it got to point where it wouldn't start at all. Lights, horn, radio...everything electric would work, but care would not turn over ... not even clicking.

First I replaced the battery posts, but no change.
Second, I thought it was starter. had it checked, but it wasn't the starter.
Third, I tried jumping the starter with a wire from the starter to the battery. It worked.
Fourth, I thought it was either neutral safety switch or ignition switch.
Fifth, i replaced the neutral safety switch, but no change.
Now, I attempted to jump the starter again, but would n't work.
I've put off buying the ignition switch because brand new it is quite expensive.

Have I overlooked anything? Anyone have any ideas.