Please. You said it's 15 muni per mine. Thats half of 30. Now you're saying it's 8 times cheaper?
All I'm saying it it already pays for the cheapness by being AI only. There's exactly one vehicle which needs to fear it: the m3. Anything else will come out alive no trouble. Therefore it shouldn't be punished by having signs too.
My only point us that it shouldn't have signs
Each patch is 4 mines. Each of these mines is equal in size to standard mine making it as possible to hit as standard mines. Two of them can wipe a squad so whole 15 muni patch can potentially wipe twice. There is no point to refer to whole minefield in any way as every patch can be placed separately no problem.
It is also not true that only m3 takes damage from it. What about wc51, m20, UC, greyhound, captured axis light vehicles? Even flak ht takes damage.
Now read my posts again, this time trying to understand them.