You can.
If you're going to keep it with no idea of resale, you're good to go.
If not, a perfectly good Squier or other bass redone with all Shaller or Gotoh, 'upgraded' pickups and wiring, and a within-an-inch-of-its-life pro setup is going to get you the job of reselling (to break even) a REALLY nice thousand dollar bass with 'Squier' on the headstock. And just like a car with all kinds of add-on tuner bits, you'll never see that investment returned, because WHO's going to pay that for a $399 Squier?
Pick One.
It's like any other manufactured product: Time and Material. The better sfuff is built by more skilled and expensive builders which sets the price.
Fender Custom Shop pieces are built using as good materials and parts as money can buy for as long as it takes by the most experienced people in an expensive economic location.
A Squier is CNC'd from far cheaper parts and woods by assembly line guys turning them out quickly in a far cheaper environment. CAD/CAM and CNC closes a big part of the difference in quality, and the buyer decides what works for him and votes with his wallet.
And every player has their own idea of how much $$$ a bass should cost for their needs. At one time, American production items were obviously better than imports. That is simply no longer the case in a world economy, and a CNC-driven plant with a trained-up, motivated workforce can be set down anywhere in the world where capitalism will flock to for an advantage.
Your new bass and big screen are in here somewhere . . . .
And this is in just about any consumer item you can think of: IF you took your average WalMart and reduced the stock on the floor to ONLY US-made goods, with what you'd have left, you could just sell it out the back of a U-Haul truck by the front door.