You really do get what you pay for, you know....
There are a number of major issues with solar power, especially if you're going to be building a solar farm to power something.
The real question is: what are you actually aiming to do?
The complexity of a reliable, robust solar panel infrastructure, with storage and regulation is fairly high, and unlikely to be adequately described on a blog!
The folks that charge you per hour will probably save you a fair amount of money in the long run, and will also avoid problems associated with being licenced to do certain types of electrical and installation work.
Sorry if this sounds snarky - this kind of project can go fairly pear shaped if it's not thought through thorougly.