Just for the record, On the Elevation tour Adam used his late '60s model sunburst Fender Jazz (as on the song Elevation)
He also used a Lakland "Joe Osborne" custom bass in natural finish and maple neck. And his famous main axe that has been with him all these years is a 1964 Fender P Bass (CBS era) with a 1966 Fender Jazz maple neck. THis is the one with a mirrored pick guard, Bad Ass bridge and as of this writing almost all of the original sunburst finish is gone. (most recently seen in the Beautiful day video and played on Bullett the blue Sky during Elevation tour).
He also owns and has used a 1950's era Pbass white sa in Pride on Rattle and Hum Video (often mistakenly referred to as a "Tele" or "Telecaster" bass; these were originally called Precision or "P" basses and were first introduced in early 1950's) the "Tele" design evolved int othe now familiar Pbass design aprox. 59-62 more or less.
If you are wanting to know the prices Adam paid for these, you'll have to ask him
As for how much you would need to buy them, prices posted by others here are close, thousands of dollars basically.
However, if you are wanting an affordable option that gives you a close replica of Adam's basses, consider "Mexican" made Fenders (usually sell for $350-$500) They are of fairly good quality and sound and play almost as good as the American Made; they are available in Natural, white, black and for a few bucks more a "simulated" sunburst. An American made Fender will run ya about a grand.
If you are really on a tight budget and not needing absolute authenticity, look at Fender's Squire pbass, (about $200)
cheap, not a "seroius" axe, but not bad for just startin out or as a back up bass.
In fact if you were handy with a paint sprayer and such and had the time and patience, you could by a cheap Squire or Mexican P Bass and strip it, repaint it and attempt to mimic Adam's old '64.
some great resources for bass stuff:
thebassplace.com
geartrader.com
oh and ebay of course
good luck,
happy bassing
"Adam"
U2JT.com