I have sanded the floors of three flats over the last couple of years, and
it is very soon the time to do another one.

I have always used Ronseal Diamond Hard (satin), and the results have always
been great. However, considering the price of the varnish - ~£35 for a 2.5L
tin, I have always used a floor sealer 1st which saved on at least one if
not 2 coats of varnish at a fraction of the price. I used the Screwfix one
with a runny-honey consistency.

Unfortunately they seem to have stopped stocking it now. Any idea who does
them at a reasonable price? I am looking to cover around 30m2.

TIA.