[jackal]

Ok well the 60 is more expensive because it is powered by 6L6 tubes:

Peavey Vypyr Tube 60 Modeling Guitar Amplifier Features:
60 watts
Four channels with 3-band EQ, master volume, and pre- and post-gain controls
Real 6L6 tube power
One 12" custom-voiced modeling loudspeaker
11 editable rack effects
11 editable stomp-box effects
Up to 5 effects simultaneously
On-board looper
On-board chromatic tuner
Up to 400 presets with optional Sanpera™ II footswitch
Studio-quality USB computer interface
MIDI In
Tap tempo button
Studio-quality headphone output
MP3/CD/Aux input
Patented TransTube® technology in the preamp


And the 75 is cheaper because it is not, is is all solid state, resistors and capacitors no tubes:

Peavey Vypyr 75 Modeling Guitar Amplifier Features:
75 watts
Four channels with 3-band EQ, master volume and pre- and post-gain controls
One 12" custom-voiced modeling loudspeaker
11 editable rack effects
11 editable stomp-box effects
Up to 5 effects simultaneously
Onboard looper
Onboard chromatic tuner
Up to 400 presets with optional Sanpera™ II footswitch
Studio-quality USB computer interface
MIDI In
Tap tempo button
Studio-quality headphone output
Exclusive Power Sponge™ attenuator
Patented TransTube® technology in preamp and power amp


Now this is just my opinion, but Tubes(so the 60) will sound better, have a warmer feel to the sound, but the maintenance will be higher(tube change about every one year = 50-100$)
but the solid state will not need that, although if anything goes wrong will the solid state amp it will be much more expensive because it will need alot more work to get it going again - usually.

In my opinion if you have the money to go with the 60, then do it, but if you are like me and have shallow pockets then the 75 will work just fine.

If your wondering on volume the 60 and 75 will be almost exactly the same volume.


hope that helps..

JB