Fair enough and in that case, I could also contend that since the BFL days, I was able to purchase Corsair CX500s 80 Plus Bronze PSUs at the Egg at a final cost of as low as $9.99 ($39.99 listed sale price minus $20 rebate minus $10 instant promo code discount) and in turn, used those rebate cards to acquire more CX500s at virtually zero out-of-pocket cost.  They have powered BFL, Cube, S1 and currently, S3 miners without missing a beat.  My point is that we really can't mix in discounts, rebates, refurbished units, resale price, etc. and expect to have a controlled comparison (hence the last sentence of my last post).  I think the most sensible way to approach such comparison in order to have a modicum of control with such a variety of complicating factors is to compare the list price of a brand-new Bronze and a brand-new Gold PSU (not refurbs and excluding complex factors such as discounts, rebates, resale value, etc.) with identical/similar wattage rating within a brand as prices vary extensively across brands of identical/similar units.

Since this is an S5 thread, let's narrow it down to the 750W PSUs.  The following is a link to a comparison chart at the Egg with a sampling of five 750W Bronze and Gold PSUs ranging from the cheapest Bronze (Logisys @ $64.99) to the mid-higher end Gold (Seasonic @ $129.99).  Note that there are more Gold PSUs between $129.99 and $199.90 which makes the average price difference to be way more than just $40 across different brands.  But let's focus on the "within a brand" comparison which is between the Corsair CX750 Bronze @ $84.99 and the Corsair RM750 Gold @ $119.99 -- a difference of $35.  That's  almost $40:

Egg comparison chart of five 750W Bronze/Gold PSUs

In the end, it's how one justifies it.  I think it's more like a choice of either enjoying the savings now or enjoying it later when the price difference will have been recouped over a year or two later.