Endurance class for Thailand did not cost 200M USD. Contract was for 200M SGD in 2008. Current weakened USD exchange rates works out to about 144M USD, otherwise, it would be about 120-13M or so.
Don't forget about manning requirements as well. For comparison, the Endurance class ships are longer and about the same beam and draught, with a lower official displacement and half the crew.
PS: looks like the Indo built Makasaar was 30million, not 15million.
Indonesian Navy Receives New $30m Warship - The Jakarta Globe
I assume the Makasaar are built to commercial standards?
Out of curiosity, has the RMN attempted any large scale humanitarian support/disaster relief missions overseas? Large scale being subjective of course.
Does the RMN have a need for 4 upgraded Makasaar + Absalon class ships like you're suggesting? Does the RMN need that much sealift capacity? That's also a substantial increase in ship crew. Each of the Absalon class was estimated to cost about 220M in 2006/7 dollars without the missile suite and certain other features. They aren't exactly cheap, even if the Makasaar are.