Yep, you are right about HDDs. Its just like PTCL is doing these days. Selling 1MB for 1200 & 4 times greater connection , 4MB at 2k
About RAMs, DDR2 & DDR3 both require separate motherboard. For DDR2, you need a mobo which can support DDR2 and vice versa. DDR2 is the default memory type you can use with LGA775. However there are mobos available now which can run DDR3 for LGA775 but they are a bit expensive. (For instance, ASUS P5G43T-M PRO @ 7.2k ... which is certainly expensive as compared to Asus P5KPL-AM i mentioned in thread which costs 4.5k ... And if one were to spend 7.2k on a LGA775 mobo anyway, i would recommend him spending on a LGA1156 mobo which costs just a little more i.e. 8.5k)
About RAMs, DDR2 & DDR3 both require separate motherboard. For DDR2, you need a mobo which can support DDR2 and vice versa. DDR2 is the default memory type you can use with LGA775. However there are mobos available now which can run DDR3 for LGA775 but they are a bit expensive. (For instance, ASUS P5G43T-M PRO @ 7.2k ... which is certainly expensive as compared to Asus P5KPL-AM i mentioned in thread which costs 4.5k ... And if one were to spend 7.2k on a LGA775 mobo anyway, i would recommend him spending on a LGA1156 mobo which costs just a little more i.e. 8.5k)