Sorry, I should've been more clear. We are upgrading our park tickets. We had considered upgrading to the Frequent Fear passes, but the Saturday night would be the only other night we would probably be able to go and we had already talked about upgrading the park passes, so this seemed like a win/win.
As others have mentioned, if the reason for the upgrade is the HHN ticket, then it doesn’t make financial sense. But I think I saw you mention that this is your first trip down, so upgrading makes a lot of sense.
1) You get a free HHN ticket every year. So if you go toward the end of September this year, your pass will still be active next September, and you can go for free in early September before it expires.
2) After 4 express passes and early park admission are game changers. You can come anytime, stay anywhere you like, and still haveEPA and EP. Premier hotels are getting more expensive and are often selling out, making it expensive or impossible to get EPs on some visits. Some holiday and HHN weekends are selling out in all hotel levels, making it impossible to stay onsite anywhere. With Premier, you can drive down on a whim, stay at a cheap offsite hotel, and still have Early Park Admission everyday as well as after 4 Express Pass.
3) There are some other miscellaneous perks like free valet parking (not on nights of special events like HHN) and additional food/merch discounts that sweeten the pot, but aren’t really game changers.
Basically, I think you are in the sweet spot where Premier is an extra expense upfront that will save you money over the course of a year. You live close enough to drive (and thus have a car - so no rental fees), which makes staying offsite particularly attractive because you can save money on the hotel cost, avoid onsite hotel parking fees (no matter your level you always pay to park at UO hotels), and can choose less expensive offsite food options.