So you are not buying the software, you are buying a license to use it for one year. After that year is over, you can no longer use the software unless you purchase another license.
That's how I read the "1 year license" limitations initially. However, after asking for clarification, the licenses allow perpetual use of the software, but they limit the upgrade window to 1 year (which is pretty common for the full-price software anyway). I think that the 1 year limitation may also apply to minor updates that might normally be free (not sure about this - I think this depends on how the vendor distributes minor updates). They have updated the descriptions for most items to make this more clear. There is also some discussion about this on the forums.
It's not clear to me what exactly is meant by minimal support. Some of this software has no on-line support presence (like a forum) - for example, UpdatePatrol does not have a support forum. I usually like to see an active forum for software that I buy, since even if you don't have any problems you can often just get good ideas from reading how others are using the software. However, there's no forum for UpdatePatrol whether you pay full price or not.
In this case since I could try before buy and the cost is $3, I figured the risk was pretty minimal.
That said, I remain a bit skeptical for some reason (if it seems too good...), but the entry cost was low enough (€5/$7) that I figured I'd take a bit of a gamble. My guess is that the vendors are using this as a loss-leader of sorts and are banking on getting some real revenue from major upgrades after the 1 year.