Have you taken a look at the Kingston ValueRAM line of memory? It's definitely much cheaper than the Toshiba/Kingston line. Though the ValueRAM may be a little more expensive than the memory you mentionned, but it has a lifetime warranty.
I believe the RAM you need at minimum is a DDR PC2700 SODIMM with CAS2.5 (333Mhz), but I'm not 100% sure. There are other manufacturers that offer SODIMM RAM like crucial, cosair - look for a brand name.
I have an Toshiba A33 and I bought a Kingston KVR333X64SC25 512 mb stick. It works perfectly without any problems. The A33 is not the same as your A75 model but might have certain characteristics. I've tried a stick of 256 MB from my A33 on a A70 and it worked fine.