Latin America
In the central american and andean countries fertile farmland has never been too abundant, and some of those countries also have restrictions in place re larger land holdings by foreigners.
Countries where foreigners have bought large tracts of land over the last two decades, due to low valuations and absence of restrictions are
- Brazil, the inner, or “Cerrado” states like Mato Grosso do Sul, Mata Grosso, Goais, Tocantins, western Bahia
- Argentina
- Uruguay
- Paraguay
- Bolivia, the eastern lowlands

May 2009 market situation.
- Bolivia might be the country with the nominally cheapest land, due to leftist populist Evo Morales government and concrete risk of political violence and measures against large landholdings. Nobody wants to buy there currently and it can indeed not be recommended.

- The second lowest land valuations you find in Paraguay, and probably the best price/value and the best chance/risk ratio. The most profitable farms (soya, sugar cane), intensivly operated and close to posessing plants currently cost US$2500-3500 per hectare, cattle ranch land US$400-1000, virgin land forest covered in the semi arid Chaco region with good soil fertility costs US$80-150 per hectare.
It is significant to note that Uruguayan, Argentinian and even more so, Brazilian farmers invest heavily in Paraguay Paraguay has the region’s most favorable tax regime, 10% personal income tax, 10% VAT. On the down side Paraguay ranks rather low when it comes to transparency, quality of public services, rule of law. In other words it has many of the short comings that characterise a third world country.

- Uruguay is in many aspects the opposite case. A mature civic society with strong rule of law and a distinctive european flair.
Just it isn’t cheap any more. With US$4500-5000 per hectare for prime crop land (soya, corn, wheat), US$2500-3000 per hectare for good cattle pasture (which would include some minor fraction suitable for cropping) it is difficult to achieve an operational return above 4 or 5% anually with May 2009 commodity prices. Virgin land does not exist anymore in Uruguay.
Income is taxed in the 15-20% range, VAT being 22%

- Argentina is geographically and hence agriculturally very diverse. The heartland, the humid Pampa is comparable to Uruguay, so is the price/value for farmland (though in Argentina some top fertility crop lands rank higher still in both price and productivity then anything in Uruguay, costing up to US$8000/ha).
Cropland in the tropical north, Formosa Province, costs around US$2500, cattle pasture land of medium productivity costs anywhere between US$1000 and 2000, best pasture lands (fattening) up to US$3000/ha
Virgin land, with potential for profitable future farming/ranching start at US$200/hectare
While argentinian income tax and VAT is within the region’s typical rates, it levies an additional tax of around 20% on agri exports like soya (not on the profit but on the revenue!), which weighs very heavy on producers. Some are leaving Argentina out of that reason.

Prices for land in the region droped 10-25% in US$ terms since beginning of the global crisis September 2008, but did not drop significantly in local currency or EUR terms. The market did however turned from being a seller´s market into being a buyer’s during the crisis with much less buyers and less transactions closed compared to 12 month ago. Since very recently, May 2009, we perceive a picking up of buyer’s interest.

Other world regions
Other countries exist where fertile farmland is surprisingly cheap. Just foreigners can not be legal landowners (Russia, Ukraine, Kazakhstan, Prairie States of Canada). In Romania and Bulgaria fertile land was rather cheap for a brief period in recent years but not so any more. In the vast majority of asian and african countries foreigners can not own farmland (just lease it) One exception, and with low prices, would be South Africa but the the race and crime issue there is to be kept in mind. Land in western industrialised nations (including Australia and New Zealand) is too expensive to be discussed in this context.

Buyers of land have a basic decision to make
- buy farmland and operate it oneself, disadvantage – being a farmer is a profession not to be taken lightly and being the boss of local farm workers is not an easy task either, or
- buy farmland and hire a management company to run it, disadvantage – management fees may eat up large part of profit, or
- buy farmland and rent it out, rental return typically being in the 3% range, advantage – requires less attention then any of the above, and income being rather (though not 100%) predictable, or
- buy raw land that has potential to be converted into farmland (land banking), advantage – least attention required, disadvantage – no operational return.

Land is the ultimate limited asset, more so then gold, where more of it is continously extracted from mines. The purest play of land investment would be to buy raw (virgin) land where you pay no premium for anything man-made (like buildings, like an operational farm set up).
But here the real analysis just starts. Over 90% of the world’s raw, idle lands will for ever stay that way, without comercial value, being deserts, semi deserts, montain ranges, or lands that should be left untouched due to environmental considerations.
Virgin land with potential to be productive agricultural land soon, would have a favorable combination of climate, topograhy, soil fertility, environmental viability. If one looks for recreational potential, obviously scenery counts more.
Land that is still virgin nowadays is so usually due to being remote, difficult to reach, so the extent of remoteness would be another factor to constitute the value of raw land.

View here a June 2009 ECONOMIST article "money grows on trees"