Clever use of an inexpensive small civilian aircraft. The list price for a brand new one is 20-25K euros. Add in probably 10-15K for the remotes. Gives Ukraine a reusable heavy precision bomber with a few hundred km range for less than 40K. Less than the cost of most one-way medium-long range attack drones.
http://www.skyranger.eu/prices.html
They are also very light and small. The wings can be folded back so they can be stored/transported easily. A regular passenger car can tow them on a small trailer. They can take off and land in less than 300m so they can be used about anywhere.
They are highly susceptible to gound fire, manpads, any type of AA, and some attack drones. However given their cost, a plane making 1-2 successful attacks before being shot down more than justifies their cost.