The prices on Beverage Elements SEEM great, but here is why I ended up getting my stuff from the LHBS:
1) Shipping - expect at least 20 bucks shipping, probably more
2) Gas - you don't really think about this, but obviously if you get a tank online it's going to be empty. My LHBS price was about 25 bucks more than Beverage Elements, but there was no shipping cost and it came filled which is a 10-20 dollar savings depending on how expensive it is to fill your tank. Plus I had it in my hands same day and could immediately start force carbing the beer I had just finished aging.
Another thing is that if you get your tank from the LHBS it is guaranteed that they will fill it. I have heard horror stories about tanks bought online for cheap which turned out to be imported from China and didn't have the exact right markings to be filled - then the tank has to get certified and stamped which is not a cheap process.
That said, I do think 171 for the tank and reg is pretty high, unless it's some kind of fancy tank or a double regulator in which case it would be worth it. Without specifics it's hard to say.
Edit - by "double regulator" I mean two connected regulators for two separate pressures (typically for using different pressures for carbing and dispensing). Not a dual GAUGE regulator which is what you can get for 50 bucks online.