Thanks for the input stormer.lyn! Will definitely keep these things in mind when talking with the electricians again.

Do electricians have to be registered under Suruhanjaya Tenaga? I ask because I couldn't find the first electrician or his company at the following links:
Senarai Kontraktor Elektrik Berdaftar
Senarai Orang Kompeten Elektrik Berdaftar

Thank you everybody for your input!

Well, with cert doesn't mean do things the right way, and without cert doesn't mean things are done wrong/badly. This is M'sia so anything goes like chicken farmer (That's poultry, not anything other.....) from Indonesia coming here and becoming the "Kepala" at construction site.

So you have to decide based on other people's recommendation or from gut feeling

Sure. But no need to ask who as he is also very choosy about customers. Not worth his time to layan all the lousy customers and end up with plenty of headache.

I've finally chosen electrician B based on the following factors:
  1) He took the time to explain things clearly, offered options, and discussed the pros and cons of each.
  2) He advises against replacing things unnecessarily, often saying, "Can change if you want, but the price will be higher."
  3) He doesn't cut corners or suggest shortcuts (e.g. looping wire from an existing socket).
  4) He's listed on the Suruhanjaya Tenaga website.
  5) He works with his dad, and both his father and his father's company (which has been around over 25years) are also listed on the Suruhanjaya Tenaga website.
  6) He's neither the cheapest nor the most expensive.
  7) His office is just near my house

I'll post an update once he's done with the work—hopefully next week. Here's hoping for the best!

Just sharing my experience here...No intention to be sarcastic or what....

Based on my discussion with wiremen, most of the them are not certified or registered...If they are certified, they told me, they wont be doing such small jobs already like installing water heater and etc...

Charges is one thing, but do you know what kind of material are they using ?

Some quote u cheap but using questionable material...

Some quote u mahal but they used high quality industrial grade material..

It can be subjective...

Just sharing this as I have been dealing with wiremen for a while...

Before they quote I have told them the exact specific material I want ...

For ie, electrical wires ...ada different brand..I used one of the best brand in MY...

Then you need to tell them the size coz got 1.0mm, 1.5 mm and etc...smaller size is cheaper...

Then conduit piping...got High Impact one or not...

DB box or fuse box...guna plastic or metal...Metal is better....

Fuse ler, ada banyak jenis...

The list just goes on....

I would think lucrative is a relative term.

I got my bro's electrical contractor to lay new wiring for whole house, add plug points, lighting points, replace main db plus add sub db. He is on the registered competent electrician list. He told me his earnings from doing large project vs small ad hoc works does not differ much, but the larger project mean longer duration and more stable income.