I don't recall this information being immediately accessible.
I do recall it being a one off fee of £25.
Last month I read
In Google's Android application market, no pre-approval is required, though registration is needed for distribution. Developers need to register as developers (cost $25/year) with a Google account and sell their products through a published site. NonDfree applications can be sold after configuring the bank information.
source: bada_development_guide_for_android_developer_modified_final.pdf pp5, date 10/7/2011
while bada was free. I suspect I was reading old information, bada cost £1 for seller registration last time I checked. But I don't think Android ever cost £25/year and this was just Samsung pushing their own alternative OS.