I have a Variax 700 guitar and a 75watt Spider II amp. I am considering buying the POD XT live for €475.

Would this be a good buy? And would I be able to create nearly all the soundsa out there with this gear?
The POD xt Live is a huge step up from the spider. If you get a variax digital cable you can use the XTlive to control and power the variax, which is a really good feature to have. So yeah, i'd say go for it but browse around the net to see if you can get a better deal first - not sure if its a good deal or not, i don't know exactly how much the POD XTLive costs.

edit: I didn't know you used € in Ireland? ah well, now i do.
I like analogue Solid State amps that make no effort to be "tube-like", and I'm proud of it...

...A little too proud, to be honest.
I just bought one last saturday. Very nice piece of equipment. Makes all my stuff sound better.
Dean Icon PZ
Line 6 Variax 700
Dean V-Wing
Dean ML 79 SilverBurst
MXR M 108
H2O Chorus/Echo
Valve Junior (V3 Head/Cab and Combo)
VHT Special 6
Phonic 620 Power Pod PA
Wampler Super Plextortion
Line 6 Pod HD