I might be missing something. The original Faderport wasn't real expensive.
I don't work for PreSonus, but so far I haven't seen any promotions on upgrading. (I'm not sure why they should...) The cost to them to take one back, recondition/verify/re-package means lots of cost for little gain.
It won't surprise me if the newer ones go on sale at some point, but nobody knows if/when that may happen. (It may not.)
You can always sell existing hardware on eBay, Craigslist or other places. Sweetwater has demo units that are $50 off, that is always an option too.