Maybe I'm just cranky, but I'd be a little suspicious of anyone who's even participating in giving threads if they can't afford to participate, and who then makes sure to tell the person they're giving things how poor they are. Giving threads are full of...you know, giving people, who enjoy being generous, which is prime hunting grounds for manipulative little weasels. You sound like a nice and generous person, anon; if I were out to manipulate a nice gift out of someone, someone like you would be who I'd pick.

personally I'd stay on the safe side and just continue playing the giving game as usual. if they want to take part in a giving thread that's outside their budget, that's their business.