In general an axle is a centre shaft for a rotating wheel or gear. So In general axle shaft is on which the hub of the wheel is mounted. In a rear wheel drive, on side on the axle is attached to the differential assembly and the other side is attached to the hub.
The average cost of a vinyl replacement window is between $400-$575 per window for a double hung. That price includes the cost of the new vinyl replacement window and the installation of it. The big difference in price would be for reasons like the manufacturer of the vinyl window (which series you go with in their line), grids, low-e and argon gas for example. Vinyl casement pocket replacement window:
There is a huge range in window replacement costs -- anywhere from $100 at home depot to over a $1000 for a Pella casement window. The average replacement window cost is $300-$700 for a single window inserted into existing frames. This would equate to $3,000 to $10,000 for a home with about ten windows.