your friend is right... mountain bikes are taxable according to the customs table...road bikes for some odd reasons that it shares the same wheel size as those old normal singlespeed bikes are not...

if a dealer imports a bike, they would have hide any necessary shipping charges, taxes, or any other charges into the final price... they would not be itemizing it out for you...that is also one of the reasons why the bike would not costs the same from just a plain currency conversion of the price you saw online...
the standard answer....

try Giant (jbs bike), Merida (pedalspot), and Polygon (rodalink) first. Then take a look at the rest, if you can afford them, then go for it...

http://www.baikbike.com/bicycle-shops/

there are 2 scenarios to this...

1) you want the bike fast, and they have to fly it in separately or just flying that particular bike over in a single shipment... then i think, it is fair to pay the freight charges... tax wise i am not so sure of as tax is a grey area in malaysia as you know it... if it they really get taxed and there is docs to prove it... i guess there is no ways but to pay for it...

usually bike shops ships their bikes in batches of large quantities 2 or 3 times yearly to make the costs of the container worth it...so, even if they are willing to order it over, you might have to wait months to get it if you missed their last shipment...

2) they might be shipping it over from some shops they have connections with from neighboring countries as they could not get a single bike from their main supply source... i've heard of this being done and the declarations for taxation is a bit more murky on this one and there is high chances shipments like this gets into trouble with customs..

if they are asking you to wait for a couple of months so they can ship together with their next batch of bikes and still make you pay the extra on top of the price of that bike (which is sold at the same price as the simillar models of smaller size in their shop)... then it is questionable since the costs would have been embedded into their main shipment...

it's the same thing as if i buy my japanese domestic blu-rays, DVD or CDs ...i have to pay the tax rate, shipping charges which actually ends up higher than sites like cdjapan or yesasia... leading to the costs per album as high as RM180-RM200 as opposed to local released ones at less than RM50... it just depends if they want to tell you what you are paying for...

what bike are you looking to ship in btw, if you don't mind me asking?