it was delegated in Feb 2014
one reported sale since then (find.reviews $2,000)
with about 140 "reviews" keyword $1,000+ sales since 2004 (less than 14 per year on average), almost all in .com of course, i would expect no more than a couple of sales in the extension a year, or less... meaning even if you own something super premium like car.reviews or search.reviews your chances to sell are negligible. random non premiums are just not sellable and a waste of money.
i personally cant imagine what made you reg those
None is developed or has high indisputable value in .com (dont quote $xx,xxx asking prices, they are not going to sell for that ever)
Registrationreviews is not even registered...