Even the EIA-commissioned study I linked doesn't include that, but it is a potentially significant cost. If we take the median price of US$4702 per Texas "acre" from https://texasfarmcredit.com/resources/texas-land-pricing-gui... it works out to US$1.16/m². At 30° latitude your panels provide about 0.86 square meters of panel per square meter of land, or more like 0.3 with trackers, so the land price is on the order of US$3/m². A square meter is nominally a kilowatt of sunlight, so that's US$0.003/W of sunlight, but mainstream panels are usually only around 21% efficient, so it's more like US$0.015/Wp. Historically this has been insignificant but may no longer be with mainstream panels costing only US$0.10/Wp.

Desert land, lakes, and harbors are cheaper, so we should expect to see more panels there instead of on potentially arable land.

You can buy land in the desert for under $1000 an acre. There are places you can buy farmland for under $10000 an acre.