Don’t hate on my bus transmission!!!!
4 speed is a tank.
To OP, the sweet spot in my opinion is anywhere around $10k for an 00-05 from 150k to 200k miles. Find that one owner, maintenance for everything, and you are set!
This leaves you room for upgrades without breaking bank.
15k-20k is too high for 100 series, because as you inch closer to 20k you are close 200 series and might as well save a few more pennies for that huge upgrade.