Looking for someone to take over my web business

Due to my husband's advanced Parkinson's I plan to retire in October this coming year to become a full-time carer, and I'm reaching out for advice about handing over my clients to someone experienced and reliable.

I have a Heart Internet Reseller account, and it's essential that anyone who takes over is also with Heart Internet as Heart will simply transfer domains, sites and mailboxes with no down time. They charge a fee for this - I think it's £30.00 per site, which I would expect the taker-overer (for want of a better word) to fund.

I have 30+ clients, most of them long-standing, and most sites are not content-manageable and their owners require occasional updates. A few sites are around 15 years old and I'm sure their owners would welcome a mobile-friendly redesign.

I charge around £80.00 annually per site for web hosting + £10/£15 domain renewals.

That's it in very brief, though there are some variables which I won't go into now since this post is more by way of a 'feeler'.  My main question is this - is anyone interested, and what would forum members consider a reasonable price per site? I'm not looking to make a lot of money - of more importance is someone who will look after my clients, most of whom I have a friendly relationship with. It's also essential that this person is UK-based.

Opinions, advice and any questions welcome.