The page matters, the $650 doesn't have to.
A landing page for land does two things. It loads fast on a phone, because most of your clicks will be phone clicks and a slow page means people leave before they see the parcel. And it puts a form or a tap to call in front of them at the moment they're interested, instead of an email address they'll copy into another app and forget. Your survey PDF is good content and it belongs behind or below the form, not as the main thing.
On the $650, you can build the same thing yourself in a page builder for the cost of a month's subscription. Photos, acreage, county, access, zoning as it currently stands, price, and a form with name and phone. That's the whole page. I've done it in an afternoon and the version I built converted fine.
On the $500, that's not enough for Google search on land keywords in most markets. Clicks on anything with buy land plus a county name get expensive and you'll burn it in a week with maybe 30 clicks. Facebook or Instagram at $500 targeted tight to a radius around the parcel will get you more impressions and worse intent, but for raw land the buyer pool is small enough that reach is worth something.
What I'd actually do before either is post it on the land marketplaces and see whether inbound shows up for free. If it does, you've learned something for nothing and you can spend the $500 knowing what a lead looks like.
