£100,000-£150,000 for R&D, measurments and producing the final tooling and prototype is a figure I've seen thrown around a fair few times. Its well enough established from Irish forums I frequent as certain users who run shops etc have queried it or know from Mr Murphy's experiences
If you assume a retial mark up of 100% (which doesn't seem unreasonable for the typre of product) you're looking at wholesale price of 125/2 = ~65 for arguements sake.
After that its pure guesswork, rather than vaguely known from above.
IF selling price is 65, probably looking at varaible costs of around 20-30, fixed of 150k/X thousand units and profit of 5-10 per piece.
X=5000 units seems like a reasonable production run to reach a profitable level
Once again I will stress these are just my musings and nothing more.
Given that runs of 500 are possible the variable costs may be considerably less (though these special runs are usually variats on a standard item)