Eh, you'd have to have some seriously insider like connections to get something for $3k. Could you build a 2500 watt solar setup for that price, sure with an asterisk next to it but sure. But if you want it off grid you'd want it to be probably 4x that size which I would say you probably couldn't do at all, the reason being is you're only going to get 3-4 hours on average every day of peak solar (i.e. what your system is rated at) so you're going to need much more than that to power it throughout the day, and while you probably can find salvaged panels for cheap, the inverter of that size won't be cheap and neither will the battery storage.