Advice For Buying Land

It really depends what you want or are willing to do, your priorities and so on. Some people might actively seek out poisoned, arid or infertile land on the basis that healing it could be a greater net benefit to the planet than simply repurposing land that's already healthy.

The things I looked at when I was searching were access to rivers, distance to public transport and other utilities and elevation (not much point buying somewhere that'll regularly flood or fall into the sea). It was also important that I be able to live very close by, as that makes it much easier to work.

One of the major facets of permaculture is restorative agriculture, repairing bad land and growing things in places that previously couldn't support those things.

There are plenty of successful permaculture projects that are in places with very little water, steep slopes, etc. Obviously the better condition the land is in, the easier things will be for you. A flat plot of land in a fertile valley is great, but land like that is very expensive and likely already used by commercial farms. So one of the great things about permaculture is that you can acquire less-than-optimal land for cheap and transform it over a period of years.

+ soil tests - pfas, pesticides

Gentle slope is ideal because it give you an opportunity to work with water flows. All the other issues, like another user said, depend on what kind of project you want. In principle, permaculture is great for challenging locations, such steep slopes, because it has approaches to working with those areas that conventional agriculture doesn't. But they are still going to present an extra challenge and will always have their limitations. So the questions are how productive do you need it to be and how long are you willing to wait for it to become productive.

Wind exposure is something that needs to be taken seriously, but again there are things you can do - planting a shelter belt is the main one, but that is a significant undertaking that also will eat up a chunk of space.

I’m assuming you’re looking for advice because you’re new, rather than because you’ve done this before and you’re talking shop to check your assumptions.

Flat land is fine, but you’re going to get to use a lot more of the toolbox if you have elevation. On the other hand you will have to use more of the toolbox. Which is why I would recommend people use the space they have or can borrow as much as possible so they are more informed about what they want. In part, how your body tolerates some of the work, and what of that you can avoid by changing your practices or location.

It’s not easy to start over, but it is definitely easy than starting. At least until you get old and creaky and then it’s probably about a wash.

My property is in an extremely wet location which is great, but sometimes it rains for weeks and some trees/plants can’t really handle it. Luckily about 1/3 of my cleared land is on a bit of a slope so I can still plant these trees because the water doesn’t pool around the base of the tree and they don’t stay wet all the time.

Just something to keep in mind, sometimes a bit of a slope is really valuable.

First of all, you need someone willing to sell. That might be more difficult than you think. Unless you are a billionaire, compromises will be inevitable

Safety should be number one, no? Is the property prone to floods? Wildfires? Sinkholes? Is there terrain that could suck you in and trap you like a bog, mud, or quicksand? What about abandoned structures that could be dangerous?

Like the others have said, you can turn just about any dead piece of land into a garden of eden. So IMO as long as you don't care about how much time and energy you'll need to put in, focus on safety

In the age of climate change. Water. Water. Water.  Wind exposure is definitely an issue, wind can increase water loss immensely. Depending on your climate, wind chill can kill otherwise hardy plants. 

Dang. I'd love to move to Crete. Former professional horticulturalist here. 

This is more related to one you've already specified: sun exposure. I'm working on a cross-seasonal sun exposure calculator (shademap.app) that takes into account terrain, trees and buildings. Some of my users have mentioned they use it to prospect potential land purchases, especially ones that are hard to visit in person.