It does seem expensive but if there is something that you just can’t do without and it isn’t available in France then I think it’s worth the extra cost.
When I lived in France me and hubby were big tea drinkers (I still am!) and would easily get through a box of 240 PG Tips per month. No other brand of tea would do!! Yes, PG Tips are available in France but a tiny box of 40 in our local supermarket was about 5€ and we would get through that in a few days.
So it was worth it to us to buy them from British Corner Shop which we did, usually twice a year. We also bought other goodies, despite the cost, that just weren’t available in France or were cheaper than in France. Hubby loved his little tastes of “home” after more than 20 years in France.
Also, if you spend more than £100 delivery is FREE to France. I assume that’s still the case?!