$250 from a dealer or contractor would not have been out of line, but the $999 is %^#^%#
Grainger is the primo source of replacement motors. If you search their website with your model number, you get this:
The fan motor is not the energy hog in your system. It is the compressor and the blower on the indoor unit. Today's more efficient units DO get into special high efficiency motors inside, but you can't just drop that in. The whole system has to be designed for it.
Double check all the key stats, like voltage, hp, rpm, direction of rotation, etc. It is probably a very close match, which is why the grainger.com search found it.\
By all means, spring another $15 for the specified capacitor. Never put in a new motor and leave the old capacitor. A/C units often have a dual capacitor, with one side being compressor run and the other for the fan. Simply look at the microfarad and voltage numbers on the actual capacitor in your unit. It might be something like 35/5 . It might be 370 VAC rating, but getting a 440 VAC rating would be better just because.
WD40 will not bring an old motor back to life. I'm surprised it lasted as long as it did!
An HVAC company will have to get $400 to $600. They will spend at least an hour, because a responsible tech can't just drop in a motor because you said so. He will need to run some tests on the system and that takes time, expertise, and specialized equipment. Also, he may very will use an OEM motor, and that will be $250 to you.
If your outdoor unit is older than about 6 years, it may be 10 SEER. A new 13 SEER unit would save a lot of money, but would cost a few grand to put in.