Less than 300 for full-size is rare, IOW nearly impossible in Malaysia(except Razer BWE and Ducky 1008 IIRC). If you consider import then, those China brands like Noppoo, Keycool, Plu, Plum and so on having quite lots options that fit in your budget.

For 400, you can go for the most mainstream - Filco, Ducky(900X series) and Leopold. All should be fine.

Recommended locally available brands
- Filco
- Leopold
- Ducky

Filco MJ2 or ninja RM400 can get, try look for Cex, not sure if he's still having promotion or not. Otherwise, you can look around in Garage Sales, there are a few 2nd hand Filco.

Leopold is available from bro Cyclonechuah, RM345 with free 104 blank key caps.

Ducky you can get from many reputable sellers, eg heavyarms.
- 9008S (backlit) having sales, around RM400 with free wrist rest.
- 9008G2 having sales as well, around RM360.

Those are quality boards, you won't regret the money spent

Below RM300 for cherry mx switch keyboards? You can taobao for Keycool, PLU, or other brands

BWU is only blue switch, and is kinda aficionado type gamer mech kb

ducky G2 has variable switches, and uses a durable PBT keycap

Leopold is another one of those good brand of mkb

Razer BWU - Available in blue switch only, USB 2KRO, backlit, cheapest of all, have quite bad reputation
Ducky 9008G2 PBT - Available in all switches (but locally available Red and Brown only), USB NKRO, no backlit, PBT the most durable key cap
Leopold FC500R - Available in all switches, USB 18KRO,

When you said "last two seems pretty similar", I think you mean their appearance, is it?

Mechanical keyboard is all about the typing feel and functionality, those blings blings, appearance design and whatsoever is basically useless.

中看不中用 - Barks louder than bite...

Mionix Zibal may be? It is hard/impossible to be found in Asia.
Or may be some Cherry brand keyboards too, they are much cheaper in Europe AFAIK.

You can get Cherry MX3000 series keyboard for cheaps in Germany/Austria. Rm250 - RM300 ish
However, since these keyboards are huge, your friend could probably fit very little number of keyboards inside.