I think there's still a fair bit of less than full price Liberty around so we needn't run out for a while. If you toile a pattern in a less precious fabric, Rowe, then you should be able to cut into your Liberty without fear.
I'm not sure what cotton fabrics are regularly printed in the UK now but there's still a bit of silk printing about. Of course, the indigenous British fabric is tweed! Yummy Harris tweed, other Scottish tweeds, Linton tweeds and Yorkshire wools. Very different to tana lawn but just as yummy!