I would be interested as playing the ghost tournaments is a ton of fun and I only play silver level otherwise, so any chance to mess with diamond cards makes it more fun. Wild would be even better, but that's probably a smaller group of fans.
10k DEC is not a level I'm up for though partially due to being at a disadvantage not being as familiar with max cards as daily diamond players. So we would be more in for the entertainment if I added a 2nd guild member.
My goal with these Guild Tournaments is to host them once a month and have each one a different format and league level. That way, it allows most guild members to participate at the league level they normally play at while also showcasing which Guilds are the most versatile.
As for the entry fee, I figured 10k DEC wouldn't be that much of a limiter as it would be split between the two participants or even sponsored by the Guild itself. Depending on how this first tournament goes, I may lower it but may raise it too depending on the type of tournament and everything.