How can merge 2 (256kb) ADSL to receive 1 (512kb) speed?

hi
I live in Iran and internet price in my country is realy high. i mean for example in USA the price of internet in about 1/50 in Iran.
1mb= 400$ usa for any month, 512kb=170$
I look for one way to give me lower price.i need some hardware to work with this method:
I have 2 ADSL+2 (256kb) i like merge this 2 for receive 512kb speed with this way I can save 50 to 60$ any month so can buy 2 384kb and upgrade for make 768kb and save 120$ if like in future.my problem when i connect 2 different ADSL in 1pc i have 2 ip and have only 256kb speed.i need hardware when i connect 2 ADSL256 give me 1 adsl 512 with 1 ip to work with this speed.i need one
router but i am not sure and have not enough information pls help me.

Apparently it can be done but only if your ISP has the ability and more to the point, actually wants to do this.

It’s called MLPPP and both lines need to be the same.

Check with your ISP.

Hi,
You can Always configure Load Balance for your Two Lines. There are some examples in http://wiki.mikrotik.com

http://wiki.mikrotik.com/wiki/Load_Balancing_over_Multiple_Gateways

Pl Refer