I currently use a pod x3 multi effects pedal. Im am debating whether to buy a good tube amp to use with it, or to sell the x3 and put the money towards an even better amp.

Sell it and get a better amp, it will be better for all of us in the long run.
Squier classic vibe 50's strat, modded.
Dunlop 535q
Korg Pitchblack
Carvin X100B

Coming soon to a pedal board near you:
Analogman Sunface
Lovepedal E6
Area 51 wah
Skreddy Lunar Module
Malekko 616 Ekko
sell the pod and buy a better amp.

Kramer Focus 3000
Ibanez ATK300
Rocktron Chameleon
Digitech IPS33B
Ibanez WH10
Korg Pitchblack
Line6 UX2
Sell the POD.
Call me Wes.
Fender American Deluxe HSS Strat
Chicago Blues Box Roadhouse
Bad Cat Cougar 5
1957 Gibson GA-5
Ceriatone 18w TMB Combo
Hughes & Kettner Tube Factor
Various Ibanez TS9s
Weber MASS Attenuator
I think the pod is useful, but it depends heavily on your situation. Do you record? Do you need to nail a lot of tones in a band situation?
Keep the x3 and just start saving. Unless you absolutely need an amp soon.