I'm not a flooring expert, but I do know that laying down new plywood for flooring substrate is something that is done with great frequency and probably competitive pricing if you were to get the job quoted by a couple of local contractors. Trying to tighten up your existing floor might set you back a chunk of that budget without success in the end (they could tighten it up only to have it develop new squeaks in the future), so it's up to you how much risk you want to take there and how long you expect your laminate to stay in place.

Remove the planks and install a proper plywood subfloor.

I'm getting that sense. Thanks for the response. I"ll just have to wait for the proper timing so I can make more dust than planned. As usual, by avoiding shortcuts, I can expect a better finished product. Thanks again!

If you choose to buy yourself some time (7-10 years) I would suggest screwing down the boards that squeak. The sound comes from METAL (ie. nails) rubbing up and down on wood (the flexing boards). If they are screwed down, the movement AND the rubbing stops.

To do this you will walk over the floor (in grid like pattern) and with a red pencil/pen you will circle the areas the create noise AND the areas that make all the movement. You will then go back around and screw down those areas until your noises are reduced to the point of acceptable.

Once that is done, you can then have a look at the 'flatness' rating of your floor. If it meets the needs of the laminate then feel free to put down your new floor.

Personally, I like to see 6mm cork underlay used over top of the old wood. This does two things. It helps "eat" 1mm or so of flooring deflection (taking it from 'not flat' to 'acceptably flat") and it offers noise reduction should the old floor continue to make noise. It is an added $0.90/sf but it is well worth the cost.

Even the WORST $0.79/sf laminate over 6mm cork can feel like a dream floor.

Just a little FYI for the DIY.