Idk if you own property 10-20k $ should really not be an issue to come up with, most houses cost at least one order of magnitude more than that, maybe even two.
It also really doesn’t matter because with a property as collateral and the bank seeing investment in home solar you should probably be able to get a loan.
The important thing in this calculation is usually more along the lines of, how long does it take to get a return on that investment, and how long can I expect my panels to last afterwards, what kind of ROI can I expect lifetime. Lifetime ROI for solar should be 2-5 while being low ish risk. If your lifetime ROI isn’t at least 2, either your government does Energy subsides pretty last century, or your quote is inflated or misconfigured, or it might just not make sense otherwise where you are, this last point only makes sense if installation or grid connection are very expensive compared to normal because of the shape or location of the specific house.