When the going rate for them is $235, how can this place have them at $172.49? I don't want to assume the worst, but I wonder (like cheapo) if they're reliable.
The going rate is much less than $235 if you shop around. You should be able to get them for around $200 +/- a few $$ from fairly reliable places. The ones that carry firearms accessories usually have good deals but they don't advertise except for retail. You usually have to email or call for the best price ala Surefire dealers.