Are they made of Silver, LOL?! 
(That seems really high)
The prop replica collecting is an expensive domain. The Master Replicas studio scale AT-AT for example goes now for $1200-1500, the MR Millenium Falcon goes for $2000-2500, the 1:1 Stormtrooper helmet went for aprox $400 (and now reaches $600-700 easily). These replicas are made from original Lucas Film molds or scanned from original ILM movie used props, they are hand painted and finished, and they are limited editions with quite low editions. Most of the prop replicas increase their value in time, and just a very few are just holding their value to the MSRP.
The eFX ANH Darth Vader helmet will be the most accurate licensed Vader helmet from the Original Trilogy - the other one being the MR ROTS Vader helmet. Just look at the pics above and compare them to the Vader seen in ANH and you'll see they are very very close in appearance, all the small details are there. This is because eFX team used the original Vader helmet to do their model as you can read in the first message in this topic
