I checked this out earlier in the year albeit for a 2.0TFSI and the cost was more than I was willing to pay. Out of interest I used moneysupermarket to generate some quotes for no mods and with remap (+20% bhp). This is what I found:
Best no mod quote - Privilege £230.02
Best remap quote - Admiral £559.50
For comparison: no mod quote - Admiral £455.62
So looks like another £104 from Admiral for the remap but it's miles off the cheapest quote or £329.48 to be exact.
Conclusion: I still won't be remapping.