Yeah, the sad reality in all of this is you seem to find out that those you THOUGHT would support you are the ones who are trying to take advantage of you. Always wanting you to donate something, whether it be goods, services or money. Yet when there's an opportunity for them to return the favor they are no where to be found. They take their money elsewhere because they want to save a buck or two.
I had a business friend of ours who owns two liquor stores here in town tell us a story of something very similar to what the orginal poster is describing. He said this guy he knew would always hit him up for sponsorships his kids were selling for their local band booster and/or ahtletic booster. He said he would ALWAYS buy one and never give less than $100, many times more. He'd also buy anything his kids were selling for school fundraisers like candy bars, cookie dough etc. He said he did this for years. Until one day, he was going into Wal-Mart and this guy was coming out with a buggy full of beer, ice and charcoal. He said he couldn't help but ask him why he didn't buy that from his store. He said the guy told him that Wal-Mart's price was "a lot" lower than his price and he just couldn't see paying that price for it when Wal Mart was carrying cheaper. The liquor store owner told us he then realized that this guy hadn't bought anything from his store in years that he'd been getting his beer at Wal Mart.
He said he didn't make a big deal of it and they went about their way. Then that summer the guy called him and wanted him to buy a sponsorship for his son's summer league travel baseball team. He told him no and the guy couldn't understand why. So he told him why. That he'd supported his kids' fundraisers for years, giving hundreds and hundreds of dollars yet he couldn't even as much purchase his beer from him but rather go give his money to a place like Wal Mart. He said they got into a huge argument and ended a long standing friendship over it.