I would recommend the used Squier, assuming you love to play it. Squiers are super inexpensive, and *potentially* a great value for the money. Their quality varies a lot, so play every single one you can find until you get a feel for the variety, and find one that you can't put down. I just picked up a 1989 Squier 2 P Bass for $100 via Craig, and it's a great bass, unmodded!
If you have time to look around, look for an early 90's Squier (you can schmoogle "Fender Serial" to learn how to identify the year by the serial number) — they tend to have great vibe and playability, and the List of Craig has loads of them. Re Ibanez: personally I'm not a fan of the newer Ibanez basses, but again if you have time to look, go for an 80's Blazer or Roadstar / Roadstar II — they usually go for $300 or so, but prices are going up since hipsters are 'discovering' them.
Also, definitely get it set up and intonated by a tech that you trust. Be sure to get recommendations from professionals in your area, don't just have it done at first place that offers! A good setup of action & intonation should cost you around $20-40, and this should include double checking that the nut is cut/filed properly, frets are level (and hammering down a popup or two), etc.