Infinity has 2 new Amplifiers.
• Ref475a: 4 x 75W Full-range amplifier – Rs. 14,990/-
• Ref1600a: 600W Mono subwoofer amplifier – Rs. 19,990/-
The ref5760a was a 6 channel amplifier that has been discontinued. It has been replaced by the Ref5761, but this is not sold in Europe and Asia for now.
Therefore
- It's not sold here, but I guess it should be around $600 in the USA.
- Service is available, but warranty would not be applicable.
- Resale value should be higher than commonly available brands, but regardless of condition, car audio electronics have poor resale value. I think after 2 or 3 years of use, you can expect a 50% to 60% drop in resale. You'll get less than half the price back.
4. Since budget is no problem and you want to connect 2 woofers and 4 speakers, you would probably want the 4 channel amplifier and the monoblock. The mono would drive both woofers easily.
Your general direction is confused as of now. The Sony 222 is a budget amplifier, grainy at it's best, why would you want to combine it with Infinity amplifier? Why would you be using 2 different subwoofers?