That's surprisingly cheap. A farm near me, with similar production capabilities, recently sold for $25,000/acre. Around here, you won't find anything really worth farming for much under $15,000/acre on the low end these days.

However as you probably are aware sometimes competition among neighbors boosts those prices into the stratosphere.

Then there's Detroit where you can buy city lots for $50. Assuming an average size of 50 by 100 ft or 5000 sq feet that is $435 an acre and it comes with water!

http://auctions.buildingdetroit.org/sidelots

Also, urban soil frequently has chemical contamination. If nothing else, it often has high levels of lead contamination from mere proximity to the streets used by cars that burned leaded gasoline before it was banned.

Buying multiple distressed urban lots to use as farmland is a horrible, horrible idea. If you want to buy land for traditional farm, do it in a rural area. Urban land does not make sense unless you are experimenting with vertical farming, where the grid power and piped potable water is already available, and the local soil (if any) is not going to be used anyway.

Also absolutely no one is going to buy a house with $50,000 of taxes attached! Instead you wait until the land bank owns it and either buy it directly from them or wait for the yearly auction.

Rarely do housing sites have chemical contamination. There are however former industrial sites that do. But if you look at who is doing urban farming in Detroit it is exclusively on former residential land.

Urban farming does make sense economically. Lots of young people don't have the capital to buy good rural farmland. If you're in the city you're also near great markets but the key is growing high value, labor intensive crops like fruits and vegetables.

Unless you're an experienced farmer operating at scale you can almost always buy corn, wheat and soybeans cheaper from the farmer than you can grow them yourself.

The $50000 bill is the average code to bring buildings up to code. You are correct that this would not apply for side lots. But people can and have purchased houses for "$50" that included a ~$50000 obligation, for use as low-income rental properties. Such houses can be made profitable by leaning heavily on the federal Section 8 voucher program. And that's why those properties sell.

As for lead contamination in urban soil...

http://modernfarmer.com/2014/07/lead-urban-gardens/

https://soils.org/discover-soils/soils-in-the-city/soil-cont...

Urban gardening only makes sense for the most lucrative of cash crops, and those intended for consumption by rich humans. You could certainly feed yourself and your family with a well-managed plot, but you're going to have some trouble selling to anyone else, unless you serve an incredibly specific niche and have some loyal friends in the restaurant industry. The business simply doesn't scale. After the restaurant buys all it needs, you're back to the farmer's market, where even the top-shelf local CSA group can match your quality and your price, at 100 times your volume. Your only advantage is that you can deliver fragile-but-unbruised produce by hand with a bicycle fifteen minutes after harvest, rather than after an hour on a delivery truck. But in practice, hardly anyone needs that enough to pay the extra cost for it.

The guy growing fingerling potatoes on a 10 acre plot just past the suburbs is going to pay off their loan and then enjoy the profits, as the urban gardener works their ass off barely doing better than break-even.

1: http://www.agweb.com/mobile/land/farmland-value-guide/

But presumably we're talking about land that specifically can produce the 200bu of corn and 60bu of soybeans the the parent specified? There is most certainly cheaper land around, even locally, if you are willing to accept less production ability, but there is good reason why that land is cheaper.

The average corn yield in the US is 160 bu/acre and 49 bu/acre for soybeans, so it seems that the average land is not capable of delivering. Not to mention that there is land that wouldn't even be worth trying to grow corn and soybeans on, which would drag the average down even further if you tried.

The thing is, agriculture fertility is not the only factor in rural land price these days -- I've heard ala the linked article that investing in land for hedging / portfolio diversity purposes is popular. It's also no surprise to hear that more aesthetically attractive rural areas will fetch a premium (I would seriously doubt the area around the Grand Tetons region is just $450 an acre for instance; the linked article suggests as much).

In Australia dryland farming about half as productive is around $2,000/acre