[TheSpartacat]

You stress affordable, there, Spartacat.

Are you saying the ones on the link I gave aren't?

I hadn't seen your link DD  Took me a few attempts to find it now you'd pointed it out to me.
Must be my eyes.   
I have somehow trained myself to not pay attention to words on forums that are highlighted or underlined (because they often have some pop up ad attached if you hover over them), so I must've skipped over not noticing.

Of course, sensibly, I wouldn't contemplate purchasing just one item online. I had quite a large container of bits to get, as ya do, so it seemed very affordable to me, compared to the usual large suspects like the catalogues which also provide year round delivery service, or even the DIY stores.

If you wanted to be extra frugal though, these guys seem to be the Moles equivalent in the seed tray business.... 400 for 29.10 (before vat, but includes delivery)   
Something for the allotment shops out there?
http://www.plantcell.co.uk/cell_packs.html