I figured out my mistake or at least i think i have. Correct me if i'm wrong (i know you will). I started priceing systems a month ago and started with the AMD Athlons. I was able to get 512mb of 133 mhz ram for the system for around $400. With the price of the P4's coming down i began to look at those systems and the 512mb of PC800 ram is costing around $800.
Is PC800 the mhz of the Ram, if so this would explain the price increase over the 133mhz ram.
PC800 ram is Rambus ram which is different from PC133 ram which is SDRAM. They are not compatable so the type you will use will depend on the motherboard you buy. Currently Rambus memory is only used with the intel processors. As far as which is best...well, they both have their highs and lows. Rambus is faster on some benchmarks and SDRAM is faster on others. On thing is for sure though, SDRAM is much cheaper, as you illustrated in your post.