Something that people always ask is "How do I find a good mechanic?"
Well, here's the answer.
Go to a bigbox store and buy one turkey baster, one bottle of DOT4 brake fluid, and some rubber gloves. Put on the gloves, go to your ABS reservoir and take out brake fluid until it's a mm or two below the "LOW" mark on the reservoir. The fluid is mildly corrosive so be careful. Don't go too much below this. Put the cap back on and start the car. The ABS light should go on.
This won't impact the car's driveability other than ABS won't work, normal braking will. Don't do this when you might actually need ABS, like during winter.
Spend a Saturday going around to different mechanics, saying "My ABS light is on and I don't know what's wrong." If what comes back is anything that sounds like "brake system", "ABS relay", "computer replacement", "caliper replacement", anything other than "fluid low and I filled it, no charge", RUN AWAY and go to the next guy.
At then end of the day, simply fill up your reservoir with brake fluid and go on your way.
If you really want to screw with their heads put in an overgapped spark plug and say "I'm getting bad gas mileage" but that's more work to do on your end especially if you have an engine with buried sparkplugs.