Maybe some of the fee could go toward relevant jerseys? - which provides space for a set sponsor? Perhaps a sponsor could provide? Perhaps player personal sponsors could be applied at a fee?
I think if the event is well produced and streamed on multiple platforms, it provides a sponsor with an opportunity to obtain recognition on quite a wider scale if jerseys are displaying in unison. Therefore, the right sponsor would surely chip in?
I know people would say, 'that's not going in the prize fund' - but surely, in the grand scheme things, it increases the exposure and adds to the event and available fund down the line?
I don't know, I am just spit-ballin here. No experience in organizing or financing an event. Just observations from events I have been in. Which always have an event/sponsored shirt provided (99% of the time by the hall of the event, the producer of the event and one external sponsor, be it Zen, Fury, LiSi, CPBA or whoever else)