Yeah, I've got a MIM Jazz and Precision, both used under $275 shipped to my door. One with a half decent gig bag, one with a beat to crap road case.
The P was stock, and I changed the pup and electronics for a total of about $80.
The Jazz came with a badass II, and a fender Super 55 neck pickup and fender Pure Vintage 74 pickup at the bridge, just picked up a bridge 55 that I need to install, and new electronics, again about $80.
Neither one really needed new electronics, but ya know, once you've got the soldering iron out...
So for under $400 each, I've got two basses I love... Though not bonding with the P as much as I wish I was, used to a jazz neck.
Regardless, I wouldn't hesitate on a nice Squier VM or CV for the right price. The craigslist market is loaded with them at good prices, just gotta watch and try them till the right deal comes along.
You never get your money out of the upgrades, but keep the old parts and put them back if you sell. Then reuse or sell the parts