I would suggest a bigger entry price, just to up the ante, i mean to make a beacon you nead a nether star which is worth 25,000 and a few diamond blocks if im correct? and $20 for a chance to win something as big as that in it's self just seems OP.I would suggest a price of around $500 - $1000 depending on the amount of players rolling. and $100 - $500 on week days. lower players rolling means higher price of course.

But yea i really like the idea.