To be fair you would be a very high volume customer to be spending 60g and I think you would get a reduced unit price.
I have some 300w Tt heatpipe fanless PSU's that would be prefect for this and they don't need a motherboard, cpu, RAM so you are saving money there. They could also be used to help keep alternate blockchains ticking over and for people in countries with high electricity costs. I will be looking into ordering one soon.
You can the also consider that the rate of inflation in fiat money is only getting faster and that few lousy grand you dropped on some FPGAs is nothing will be quickly forgotten and you will break even before you know it.
I guess I shouldn't have used such big numbers, was just easier for me to calculate, but the break even point remains the same regardless of the size of your order unless you get a volume discount (which means a smaller order is in fact less efficient and slower to pay off), "before you know it" remains roughly 3 years, assuming difficulty stays sub-2mil (which it wouldn't if suddenly people got it in their heads that fpgas are some awesome way to beat the system) and the price of bitcoins remains the same. On the one hand it's true that the price could be much higher a year or two from now, but it could also be worth jack squat, and an FPGA board designed to mine bitcoins would then have a resale value of roughly nil, unlike traditional GPU-rigs which are still useful gaming devices and can be resold as such.
Until mining becomes much closer to the cost of electricity there is little incentive for people to drop on fpgas, especially those built by others. In my humble opinion of course.