Every year there are thousands of spring and summer running events across the US. Connect with race promoters and see if they have a charitable partner. If not, you may be able to promote your fundraiser to the runners in these races. Have runners donate shoes they bring to the race and then your team collects the shoes on race day. Who knows, you might just find a new resource for big shoe donations for your fundraiser.
Connect with your fundraising coach to discuss this and any other ideas, we are here to help.