Most of my bootleg knowledge comes from this ongoing Lowyat discussion which you can read and follow or even comment in.
Bootlegs are actually pretty easy to find but finding them at prices you'll be willing to pay for is even harder. I say honestly you wouldn't be paying RM30 (normal shop price) for a standard bootleg HG when you can get the original for RM45. I won't. But if you can get them for around RM20 or less, you'll want to to a certain limit (they are harder to build obviously). Even PGs won't cost too far off RM200. I will honestly tell you now that I got my PG Wing Zero Custom for RM155 (don't expect to get this price currently due to changes in exchange rates).
The best bootleg brand is TT Hongli or Gao Gao (same company, two different logos/names). It has been stated that those under the Gao Gao branding is better and I can admit it does feel like it with my most recent review on bootlegs. Don't get any other brand than this (except Gundoom) because models from Model GD/GHD, Bendi, LWDragon and so on aren't worth the money, time and effort to build.
The cheapest place to get the bootlegs is from Chow Kit, Kuala Lumpur. You can easily get there by LRT. Wholesale shops such as Jia Yang and Toy Box (not sure I remember the name of this shop correctly) have them (however, they might not sell to you under normal circumstances). I also can't guarantee if they are still selling them since I only went there by then end of 2009. If you cannot get them, don't complain to me, okay?
As for Jia Yang, where I got my PG WZC, MG Strike Noir and 4 other HGs, you need to know the "rules". To get the 50% discount, you'll need to get any 6 model kits. Any, as long as you get a minimum of 6. You'll need to ask the taukey or employee there first before you suddenly grab 6 and then cannot buy. Note that you must state that you learn about this from a forum (the Lowyat thread I linked above specifically). If you're lucky you can get HGs at less than RM15, MGs at less than RM50 and PGs at less than RM200 (bigger ones will cost more).
Exact shop location via Google Maps = 3.16387,101.697478
As for Toy Box, I read that you must find the right guy to get about 30% discount and you can buy any amount. I never went to this one so I don't much about it.
There are, of course, other shops selling the bootlegs but the shops in Chow Kit are wholesale shops. If you have a company under your name, it will make it easier to purchase anything fro them. If you're daring, try to persuade the shop to sell you normally.
Because I haven't went there for a good while and haven't heard nor read anything about them, I suggest buying the bootlegs elsewhere. Although not as cheap as getting from Chow Kit, they are still substantially cheaper than buying from a regular shop.
The easiest place to get them through out Malaysia, especially to those who live in Semenanjung, go to this Loywat thread. I never bought from him but his selling record is clean so buy from him if you can! The prices are also very good especially if you can COD with him. If you're doing postage, buy more that just one.
If you're living in Kuching, we are in luck now! Heng Kim Trading also sells the bootleg TT Hongli/Gao Gao at reasonable prices! You ca add him in Facebook and ask him directly as well. :)
I bought the HG Cherudim GNHW/R from the shop for about RM20 which is pretty reasonable as it is (at least I don't need to fly to KL).
Okay, that's all I can tell you guys, happy shopping! If you think building the bootleg is too troublesome or not worth to buy, then just buy the original Bandai version. XP