I share a video with you below that highlights the very real dangers of trying to save money by hiring the cheapest plumber you can find. Believe me, the cheapest plumber who is also a good plumber - is either never available (too busy), or raises his fees due to the demand. And so, if you find a readily available plumber who can come to your property at a time of your own choosing, be wary.
A bad plumber can - if you're "lucky" - turn a small problem into a recurring chronic issue that he needs to keep patching. If you're truly unlucky, he can turn it into an out-and-out disaster. Always check the plumber's website, his/her testimonials, their accreditations and certifications, and see how specific they are with their language. Liars and bluffers tend to say almost nothing specific. A confident plumber will be able to diagnose a problem, let you know the diagnosis, give you a fixed price quote, then fix the problem. Confidence begets clarity.
Furthermore, if you can, hire a local plumber. Local plumbers are easier to evaluate - you can usually find local people who've had experience with their services. Also, they have their local reputation to keep as well. Then there's the very practical aspect that they can arrive swiftly to a plumbing emergency if they're available.
Anyway, don't say I didn't warn you about this video - watch all 14 minutes of it. It's a shocker - the apartment was ruined...all because the landlord wanted to save a bit of money getting a so-called "low cost" plumber (trust me, these end up being the most expensive).