LW should get her head out of her backside. Someone who consistently sends cheap joke presents is sending the message that in their opinion that is all the relationship calls for, and it is downright PA to persist in responding with expensive 'thoughtful' presents. Refusing to get the message is the opposite of thoughtful.
As others have said, nobody expects presents of that kind to be kept, and the charity shop and the binmen really aren't in the business of judging your taste, so she should just offload them and stop getting so steamed up about it.
Sure, it's a pity, and annoying, that his humour is so badly misdirected. My mother and a very old friend of hers had a very long-running gag of sending each other hideous and unsuitable Christmas presents with a straight face ("I saw this and instantly thought of you") and then writing fulsome thank-you letters. I remember for example that one time Friend, knowing my mother had a particular dislike of a) stray hair and (b) Victoriana, sent her a Victorian hair-tidy (a little pot for the dressing-table, to hold hair-combings) of china painted with cabbage roses. The kicker was that Friend put some combings in it before she wrapped it, just to gross Mum out. (She succeeded.) Our whole family all looked forward every year to seeing Friend's present to Mum, and hearing the spoof expressions of gratitude read out.
Btw, what was the gist of the reply?