I've played several of the Multiplayer, browser based games. The best one I saw for paying and non-paying players was for every single "diamond (obviously they had a version that was not diamonds)" purchased for the paying players, the entire server would get like 5% themselves, but would cap out at a specific number. I think it was like 1k. So it worked like this:
Buyer buys the 3k package (gets the 1k bonus only for themselves).
Every other player (while the interest may be in specific families. I.e. I buy them, only the Cuneo's would get the trickle down) would get 5% or 150 diamonds. That would keep the paying players paying to keep ahead of the non-paying. It would give the non-paying a chance. It would keep the activity growing on the servers as you would never want to hit the 1k mark, just in case. The more active hits, the more investment or ability to charge advertisers. If you have 60k active players (quite a few more would join, per server, and it would be amazing), then you can charge pretty good money for internet ads.
Next, you could differentiate between a non-paying and a paying membership. Say it's free with ads, and for a fee you would be able to buy out of the ads. Think: Words with Friends (I know you have it on your cell phone). As a bonus, say a free player would get 3% of the diamond trickle-down, and the paid membership would get 5%. That way, you are not alienating the entire server between paying and not-paying, but you are giving an "advantage" to the "loyal" players.
Think about it. If you did something like this, every active player would have 5 accounts, one in each family. Every time one person clicked on your game, that is a registered hit. You can charge ads for that. Think, multiple levels of revenue, without alienating your angry players.
I also recommend you add diamonds to the lucky chance. Same as you do with the rest of the items. It would actually be worth it to me, if I could risk 5 diamonds, for a chance to find 40 diamonds, or 100 diamonds. Do not be afraid of inflation, as annoying as it may be. Trust me, you will have a TON of more active players staying on, if they even have the idea they can compete with paying customers. Your servers would last quite a bit longer as well.
Just food for thought.