Hey guys, i've been playing for one and a half-ish years. Currently, I have a yamaha pacifica 112j:

I've had no real problems with it, but recently I've been noticing that its tone doesn't sound so nice anymore, and it seems to give out as I play higher up on the fretboard. does the problem lie with my guitar or my amp? I have a line6 75 watt spider 3 amp.

so anyways, if it has to do with the guitar, I was wondering if buying a MIM tele or strat, or maybe a standard epiphone les paul would be a noticeable upgrade from my pacifica? or do you guys think i should save up my money and get something else in the future?

the kind of music i play is mostly classic/alternative rock, funk, and blues: chili peppers, clapton, john mayer. pretty much everything except heavy or death metal. and i won't be able to go try things at guitarcenter for awhile, so i was hoping you guys could help me out. thanks a lot.
It'd be a good idea to replace both but that's not always possible. It'd help if we knew your budget. A general rule of thumb is that amp matters much more than guitar. But it also appears as if your sustain maybe suffering because of the guitar.
Yeah, amps are more important than guitars at this point. I'd recommend getting some new strings on your Yamaha. Buy some fretboard oil too. Take off the strings, wipe off whatever gunk is on there, oil the frets, and put on new strings. It can really revive the feeling of an instrument.
MIM Teles & Strats are good
Epi LP Standard is nice too.
See what you like more and get one.
I plays guitars.
I would get a new amp if you were only to get one.

Take your guitar to a tech and explain your problem.