I don’t know about the cost, but one common technique is to sprinkle your property with so-called microdots. The microdots are have a serial number printed on them and generally include a service to register and track the serial number.
I’m of the same opinion, and as far the invisible ink idea goes, I think most crims know about that and use a UV light to check out the goods before selling. The ink is easily removed.
Also, if my 4 year old TV for example, was was stolen, my insurance would pay up for a brand new model of similar size. I would be quite happy to let the perp keep it.