They are the only dealer that meets the following criteria:
(1) They are reputable (i.e., they will actually deliver at the prices stated, and will refund if there is a problem).
(2) They often have prices that are far below other reputable dealers.
How do they manage this?
(a) Do they have special insider deals with Pentax? NO
(b) Are they willing to lose money on every trade? NO
(c) Do they have magic fairy dust? NO (I don't think so!)
The answer is rather mundane:
(d) They have low overhead costs and low inventory holding costs.
This means that you must sometimes wait a bit for the item. It means that if you visit them you may find that their facilities are "low rent". But it also means that you can get great deals, that are credible.
When a retailer can sell for less than others there is always a reason, and it is rarely magic fairy dust. Either put up with the inconvenience or pay more. The choice is simple. I prefer to wait, and have never been disappointed. Just don't expect that they can magically sell for less than others.
Dan