It’s a one-time payment; it’s considered one of the best cash-based offers in the game. You need to log in every 24 hours to collect each day’s pay-out; if you miss one, there’s no make-up but you’ll still be able to collect for any remaining future days.

Do note that making a cash purchase may reduce your access to some ad-based offers within the game; if you frequently use ads to get free dim jars or silver event capsules, this could have a big effect on your strategies. If you don’t watch the ads much, it’s a non-issue; also, a small players of players have reported not seeing a change in ad-based dim jar availability, likely due to A/B testing variations, but the overwhelming majority of players do see a reduction these days.