I can't answer the question without knowing what the subscription would include.
If it unlocked all digital content on D&D beyond for me to use and run games with then up to £10 a month. If it was more than that I might still do so but only if I was actively running a campaign right at that moment.
If it basically worked the same as it does now, where I have to buy digital versions of content alongside the physical versions I already have and at the same price (but maybe with more tools), then £0; not interested thanks.
If it unlocked all digital content on D&D beyond for me to use and run games with then up to £10 a month. If it was more than that I might still do so but only if I was actively running a campaign right at that moment.
If it basically worked the same as it does now, where I have to buy digital versions of content alongside the physical versions I already have and at the same price (but maybe with more tools), then £0; not interested thanks.