AFR
I don't know where you are, but here (USA) list price is $12.65 each, if you got quoted that by a dealer in the US, they are charging you way too much, drop me a line and I'll hook you up with some one who will treat you better

Smokey had some pretty good advice (and won a lot of races) ... on the other hand I wonder what the the Japan Grand Prix racers would say about the NISMO lifters.

I used the NISMO lifters. they're hollow, and bloody light. They have a slight convex on the face, which collapses over time. The oil you use is crucial to stopping this....actually, oil probably isnt the issue it used to be 15 years ago!!
I used Duralumin tube with chevy ends for the pushrods. They're lighter, but more importantly they're significantly less flexible. the 'off the shelf' ones sound great!
I'm currently looking for 40mm valves with a 7mm stem. I reckon this'll be the key to some great flow figures, and much lighter valves...

I reckon every bit helps as lighter followers means that is less weight the valve spring has to push back against the cam lobe. When the engine has 24 milliseconds or less to close a valve from fully open to closed @ 10000 rpm, the amount of spring pressure available and the mass of the valve train components including cam follower determines how fast the valve train can close. F=ma.
Its just a question if the titanium ones are sufficiently lighter than the Motorsport ones to justify what will be at least $65 Oz per lifter

The Nissan Motorsports lightweight lifters (twenty something grams less than stock) are $23 each last time I called them about a month ago. I thought this would also be a good way to gain a few extra horsepower by lightening up the valvetrain quite a bit (23 grams times 8, thats 184 grams total! NOT BAD!) I switched from stock pushrods to chrome moly lightweight ones from Malvern Racing and it made a difference. The car felt a bit stronger, although revs did not increase, there was definitely a few extra hp's. Go for it if you can afford it, I will sometime.

-Andy

According to Smokey Yunick, on page 77 of his book "Power Secrets" he says, "Decreasing the weight of any of the components on the valve-side of the system would significantly increase the max-rpm limit of the valvetrain; however, decreasing the weight of the components on the pushrod-side of the system did not, in any case we studied, have a significant effect on the rpm limit."
So, having said that, it seems to me that it really isn't worth the effort. But hey, you might see different results. Go for it!

I heard from some speedway people that some litre sprint "A" racers in the past used motorbike ones from the Ducati get this!?!?
pushrod twin cams!!! apparantely they are some of the lightest pushrods around. Otherwise is it possible to mod holden 6 aftermarket ones??

I might be interested in the titanium ones depending on the finished cost

How much are they and what is the weight?

an easier way might be to just get the factory light weight lifters. the part number is 13231-M0820, according to Nissan they weigh 24 grams LESS than the standard A series lifter.