I am going to preface this with the fact that it's recently become obvious that I should be assessed for autism. I have no idea if it's relevant but I thought I'd mention it just in case.
I recently did some work for someone for free. They had approached me in my professional capacity but it became clear that they could not afford my prices (and would struggle to afford anyone really). I liked them and considered the job one that would improve my skillset anyway so I offered to do the work pro bono. It went well; they were happy and we all enjoyed the experience.
Here's the thing: they have sent me a gift. It is not a small gift and, although it is probably only about a fifth of the value of the time I gave them, it is not inexpensive. It is a really thoughtful kind gift but I feel awkward about accepting something from them when I was really trying to save them money for something important. And I don't really know what the etiquette is now - is it ok to email thank you? Do I gush? Do we end up in an endless spiral of thank yous? And actually should I accept it at all? It's a couple of hundred quid - I thought they might send me a bunch of flowers, I didn't expect this!
God I realise I am an arsehole but I've never really known what to do with gratitude or compliments. Could someone advise me please?