You don't need expensive gear, but you should have serious gear if you want to be serious about playing bass. You can get a used US P bass and a 5 string Stingray any day in the classifieds for under $2k. A pro amp can be had for another $1k. With that setup, a strap and a cable, you can do just about any gig from bar room to large stage and not risk getting turned down for a gig because of your gear. $3k is not expensive when you compare to what other instruments pay and you don't need to buy it all at once either. Bass gear is fairly cheap.