If not mistaken its 150.

But I think depends on location too, so why not just give them a call.

If you're living around WPKL, you have to go to JPN KL HQ at Jalan Duta branch to apply for outside marriage. They will look at the date and the availability of their Registrar. Fee may be imposed.

Yes.

But only if the ROM you going to do is around WPKL area.
IF you going to do it outside WPKL area, you have to go to the relevent state HQ for to book the registrar.
But the marriage application form must be submitted to WPKL since you live in KL.

Example: Male (KL), Female (Selangor)
Where to submit form? Male to KL. Female to Selangor.

You must submit your form according to your current address on your IC.

The condition to do it in Tian Hou Gong is at least one of you needs to be Buddhist, as registered in Jabatan Pendaftaran Negara (JPN). My registered religion is actually "Free Thinker", but luckily my wife is "Buddhist".

My wife is from another state, so I did it in Tian Hou Gong. The fee I can't remember how much, but if my memory serves me well, it is like around RM 80. You can call up Tian Hou Gong first and they will guide you on what documents from Jabatan Pendaftaran Negara (JPN) that you need to fill up. Tian Hou Gong number is 03-2274 7088 (from Google).

Then after that, just arrange a day to go to JPN and fill up the necessary forms. You will need a commissioner of oath (pesuruhjaya sumpah) to stamp on your forms. You can actually find one in the JPN near Hartamas:

Jabatan Pendaftaran Negara Malaysia,
Wilayah Persekutuan Putrajaya, Kementerian Dalam Negeri,
No 20 Persiaran Perdana, Presint 2,
Pusat Pentadbiran Kerajaan Persekutuan,
62551 Wilayah Persekutuan Putrajaya.
Telefon:03-8000 8000

http://www.jpn.gov.my/alamat-cawangan/

I took half day leave and went on a weekday. The JPN is basically empty, so it is pretty quick. Just inform them you will do it in Tian Hou Gong and they will guide you accordingly. The commissioner of oath is also there, at another wing of the complex. So you can actually complete everything at the same day. I took less than half an hour or one hour, so it was pretty quick for me. Hope it goes the same to you. Oh, remember bring passport size photos there. I think they accept both blue and white background. I used white background passport size photo. But it is best if you call up and double confirm.

Then you just bring the documents along to Tian Hou Gong and register a date for registration and pay the fee. After that, all you have to do is just wait for your big day.

Hope this helps and good luck.

I did mine at Sage, The Gardens MV.

Easiest will be to go to JPN at Jalan Duta and request for that. They'll tell you what you need to do. Inviting the registrar from JPN to conduct solemnization outside will cost about RM500+.