Hi Jakky
I'm sorry if you thought what I said was misleading but my message did say that the minimum spend was £5. Like you, however, I purchased ten poundsworth of credits but only because that seemed to be better value for me.
The stepping-stones site explains the charging structure before you register and the charge for viewing the same piece, or half of a piece, of a census (hundreds of pages) for two weeks is 50p. The only drawback as far as I'm concerned is that there's no index so it's quite time-consuming but two weeks gives me plenty of time to search. I make a note of the date I start viewing a piece and when I've got all the information I need (or think I need!) or at the end of the two weeks, I use another 50p credit and, usually, move on to another piece. Importantly, unlike on other sites, unused credits are not time-limited.
I don't know how long the site has been operating but if I'd found it earlier I'd have been saved a fortune in payments of £7 each (plus hopes dashed and heaps of disappointment) when I've purchased incorrect certificates from the GRO.
The first piece of the 1841 census I looked at confirmed a link I've spent the last three years trying to establish and gave me two more generations of our family as well. That, for me, was worth the whole ten pounds but at that stage I still had twenty four credits left.
Best wishes
Marie.