Well, I've been looking through a ton of stuff, and it seems like the best deals I can find on anything are the Eheim classics through Drs. Foster and Smith. Really, those are Eheim Classics going for about the same prices as Rena's XPx filters. $80 for the smallest one isn't bad.
NewWaveFish is selling Jebos cheap on ebay, and in looking at them, a lot of the newer reviews says they're decent filters. The flow rate is lower than what Jebo claims them to be, but for the price, it's not bad. With that store on ebay, I can get 2 of the 829 model- 5-stage filters that pump 396 GPH and are rated for up to 200 gallons each for $172 including shipping. That's $86/filter. I think I'm going to go with that. I'll put one of those on my 90 as a secondary, and have the other one to use for my axolotls. Two o those for $172 compared to one 2217 for around $150 after shipping.