Sorry for reaching back in time, but I wanted to address this:
Don't use the XP budget table to label your encounters as "easy" or "hard," or try to recalculate what "easy" and "hard" mean based on the party's equipment. There's no meaning in those labels once the fighting starts, so why bother nailing it down?
What I do is look at the "moderate" column of the budget and use it as a reference for what non-geared, non-optimized adventurers can handle. I then use the "hard" column if the party is well-geared or optimized, and I move over to "deadly" column if both. This is what I use as a baseline for what I consider a moderate challenge for this party.
If that still seems too easy, I can adjust from there, perhaps using the "deadly" column of the party's level +1 as my new ceiling.
To be honest, though, I usually don't bother with the table. I prefer to plan encounters based on what is called for by the narrative. But the table is a nice reference when I'm unsure (or don't care) how many monsters are in a certain place. The only real purpose it serves is to keep you from inadvertently killing the party, right? So just use your instincts and get a feel for what your group can handle, and everything will be fine.
It's far more art than science!
Speaking from my experiences building encounters for a 5e group with a reasonable amount of magic items, I'll say you're on the right track, but you're looking at it ... oddly.5e, on the other hand, does not provide any guidelines on how to adjust encounter difficulty for magic items. So, assuming a CR 17, 18,000 xp Adult Red Dragon is a Medium difficulty, moderately challenging encounter for a party of four 17th-level PCs with no magic items, how would it change if the PCs have, between them, 9 uncommon, 4 or 5 rare, 3 very rare and 1 legendary permanent magic items? Would the encounter difficulty remain Moderate, or would it now be Easy? If the encounter difficulty does change, and the DM wanted to adjust the encounter difficulty to make it Moderate again, how much more xp worth of monsters should he add? Would another Adult Red Dragon be enough? Would it be too much? It really isn't clear to me.
Don't use the XP budget table to label your encounters as "easy" or "hard," or try to recalculate what "easy" and "hard" mean based on the party's equipment. There's no meaning in those labels once the fighting starts, so why bother nailing it down?
What I do is look at the "moderate" column of the budget and use it as a reference for what non-geared, non-optimized adventurers can handle. I then use the "hard" column if the party is well-geared or optimized, and I move over to "deadly" column if both. This is what I use as a baseline for what I consider a moderate challenge for this party.
If that still seems too easy, I can adjust from there, perhaps using the "deadly" column of the party's level +1 as my new ceiling.
To be honest, though, I usually don't bother with the table. I prefer to plan encounters based on what is called for by the narrative. But the table is a nice reference when I'm unsure (or don't care) how many monsters are in a certain place. The only real purpose it serves is to keep you from inadvertently killing the party, right? So just use your instincts and get a feel for what your group can handle, and everything will be fine.
It's far more art than science!