Yet another memory question-voltages

Hey all, hopefully this will be the last question I have to ask you all for a while, as comp should be ordered this weekend.

Thanks oodles for all the help, you've helped me get my knowledge caught back up a lot.

Still the mobo I'm looking at while it doesn't list a required RAM voltage in the manual does show the default being 1.8V(though says I can change it) and all the tested ram they used was all 1.8V. (both the 533, and 667 DDR2 they tested it with).

I am trying to get away with value RAM as this is a budget system and the cheapest 533 DDR2 I can find runs at 1.9V. Are chances probably good that I can just go into the bios and change the voltage and then boot up or should I go ahead and pay the extra for the 1.8V?