I (as someone without a need for any drone and therefore without having looked at enough prices of drones to have any gut instinct here) was curious how much that first one you linked - the Marlyn UAV - might cost, since the company only says to contact them for pricing.
This page [1] suggests $17k, is that likely on the money (pun intended, sorry) or just a random scam site?
don't think that's a scam site, though it probably has a healthy profit margin. that price is within the range of normal for a fully built surveying drone for use by people who aren't interested in getting into the technical details of pixhawk/ardupilot/arducopter stuff and building their own. They're sold to surveying companies, mining companies etc.
go look at pricing for the DJI Matrice 30 (M30) for some comparisons...
This page [1] suggests $17k, is that likely on the money (pun intended, sorry) or just a random scam site?
[1] https://volatusdrones.com/products/atmos-marlyn