A few options I’m coming up with:
As previously suggested, spend the money on staying at one of the deluxe hotels and getting EP, so you can skip the lines. I’d also suggest staying at Hard Rock. The theming would be the most appropriate, and it is the closest to the parks. Portifino is more romantic, Royal is more girly to me with a Hawaiian / Polynesian feel.
Look at tickets to the Blueman Group. This would be fun, but I don’t think it is anything all that over the top.
Check out the Universal VIP tours. The website lists them starting at $189, so I’m not sure if they would come in too far above your budget, but worth at least looking at. I think a VIP tour would definitely make this a one of kind memorable trip.
Is there a different park or attraction he’d like to do? Kennedy Space Center? All the coasters at Busch Gardens? Busch Gardens also has a VIP tour that costs much less than Universal’s. Indoor Skydiving, maybe? A concert or something else that might be going on during your dates? I’d check an Orlando event calendar to see what might be happening while you are here. Is he into Star Wars or virtual reality? You could check out the Void at DTD. What about an escape room, airboat ride, or a race car / exotic car driving experience. There are a few different ones of those available at different price points.