I have great experiense of drafting good players even when finishing high up in the league. So i would strongly recomend to put 20k into the draft.
$20k is not the max, as the OP was originally recommended to do by another poster. And you said it yourself,
you have a great experience in the draft, but that's not the case for everyone. I strongly believe the best advice is to commit what you can afford and what you are comfortable investing in scouting. Personally, I alternate between $10k and $20k depending on my income that week. That's what works for me and what I feel comfortable investing. There's no guarantee in scouting/drafting, so it's mostly a personal decision.