The ELM Bluetooth OBDII scanner from Amazon is like $12-15 and should be a quick setup with free phone apps. I've had one for 6-7 years, and it's not bad for limited use.
After that, look into various gauges like Aeroforce, PLX, and others that get into the $150-200 realm. Not sure anything's in between. Beyond that, you might as well go for HPTuners at $300-500, for full tuning ability.