I think $2,500 for a 4.7kw system is pretty good.
Very good; too bad that is not what you have.
The group I worked with last year would install either roof or ground mount for about 10 - 30% more than you are paying but we used new, good quality parts and an inverter that could handle shade.
When you install pay attention to grounding. Those expensive bolts you are skimping on are code rated for PV.
Not happening with out other people's money.
Unlike some people I don't need the government to help me pay for stuff I want.
According to DoE in 2017 around $1 per watt of what was charged for a solar install made up the companies profit, overhead and labor.
That dollar per watt doesn't do the consumer any good.
The solar installers here want just under $3 per watt for a 6kw system and just over $3 per watt for a 3kw as of April 2019.
As of today the cheapest DIY kit I can find is just under $2 per watt for a 11kw system that uses superstrut.
I'm well aware of grounding and my stainless bolts exceed code.
I'm not using the cheap grade A or grade 3 stuff I have seen on a lot of installs.
Shading will be taken care of with a chain saw and an air rifle.
To take care of shading with an inverter you need a big inverter with optimizers or micro inverters. Both options are fairly expensive with micro inverts pushing 25 to 40 cents a watt and something like a solar edge with optimizers pushing 30 to 40 cents a watt.
I guess you could always tempt fate and go with way cheaper no name chinese stuff.