I've rented my way to silver for 3 seasons. According to my report card from https://kiokizz.github.io/Splinterlands/seasonReportCard it has been profitable every single time. However my rental costs are a bit lower than yours at about 800-1200 per season, probably since my own collection is starting to shape up. I think overall it is worth it, you only have to hit 1 jackpot to pay for multiple seasons worth of rentals, and then you can start turning a profit