Having tried all those basses it's surprising that something hasn't jumped out at you! Do you feel that your playing is not competent enough to feel and hear what is working for you?
If that's the case all you can focus on is feel. The neck, ergonomics, balance. Forget Name, color, electronics.
The costs of the new instruments on your lists start pretty low, probably $200 or so and range up to $6-700. There is a big jump in quality from the bottom to the top, but the lower priced instruments can offer a beginner a great tool to learn on. If you lean Squier I would recommend the VM and CV lines for better quality and consistency. I recommend you buy new from a reputable place that will throw in a setup and be responsible if a warranty issue arise. Only if you have access to a qualified person to help you appraise and set-up or possibly repair should you consider used. One thing for sure yo can get really nice, giggable instruments within your price range. If you are unsure about your need or if you will stick with bassing buy a popular choice so you can flip when you want to upgrade or need to sell.
