I put this together for under £300 with careful used purchases, done over a couple of years though! Fishman Piezo bridge with a Bartolini preamp, skimped on the tuners (Wilkonson) and pickups (Duncan Designed) to keep the cost down with an eye to upgrading them when suitably priced parts came up but I never bothered. Neck is Mighty Mite (back before they shot up in price) and the body is from an old Cort built Hohner. Looks, sounds and plays like a much more expensive bass.
I wouldn't immediately discount cheap hardware from AliExpress etc either, I have a Schaller copy bridge fitted to an old Jazz bitsa which has been great and I have one of these on my Cort which is surprisingly heavy and all I need in a bridge:
https://www.aliexpress.com/item/A-Set-Chrome-Vintage-L-Shape-Saddle-Bridge-for-5-String-Electric-Bass-Guitar-Top/32701082348.html?spm=a2g0s.9042311.0.0.27424c4dEVbgCU