Please understand that Spector does indeed make wonderful instruments. It's their entry level product that doesn't quite live up to the "best bass in world" title, and neither does anybody else. $500 for a brand new bass is pretty cheap and that isn't leaving any room for extras. I was shocked mine came with such nice electronics. Now the Legends come with EMGHZ p'ups with the Spector TonePump preamp and they sound like stale garbage. Upgrading the preamp does wonders.
Their EuroLX line is great, they play great and feel excellent, but you pay more for that. A LOT more. Used they go for almost a grand and in some cases more. Don't swear off Spector just by the experiences of others, your results may vary.
The main point is, factor in the cost of a good setup if you buy a used instrument. If you buy new, only buy it from a shop that will include a full setup (yes, even fretwork if needed) and fresh strings in the purchase price. It's new for godsakes, it should be NEW.