@Derrick Holmes, first off, welcome to BP the bestest of all REI sites...I would commence by warning you off of land, as an investor that bought, sold, rehabbed, subdivided and rezoned land both raw and improved, it's by far the trickiest of all real estate endeavors; HENCE more rewarding. The issue with land in general is its stark trickiness, there's no way to set a general rule of thumb as to what prices ought to be offered or what an approximate value would be, the reason? Fluctuation, zoning, REzoning, demand, topographical data, etc...
To give you simple examples as to how big of a spread between one deed transfer and the next; I have seen land that was bought for 1.25M only to be resold for 80K, a multiparcel that previous owner bought for 500K resold for 5K, etc...
Bottom line, in REI land is by far the most rewarding yet the most devastating of investments; and, since you're new to real estate, I think it's best to read about it and do extensive research first and foremost. Also, there are no reliable comps you can count on simply because of the huge disparity between one transfer and the next along with scarcity of information sharing.
A good tool that can give you an approximate value & help is the GIS system, most GIS will breakdown the land value and the improvement value. So can go into a neighborhood's GIS system and look up what the individual parcels are assessed at and omit the building (also referred to as improvements), typically the real value of nearby parcels is somewhere between 50% and 75% of what the county claims; example: if the Fredericksburg GIS system claims that a certain house's land is assessed at 50K then your investor should NOT buy it at more than 37,500 at the VERY most.
One MAJOR point to take into consideration is: an investor that you will help buying a parcel of land is an investor that will have less money to make future purchases.
Good luck, and fee free to shoot me any questions as I'm very familiar with the Fredericksburg area and won't hesitate landing a helping hand to fellow BP.