Well, they will be cheaper to operate.I like these ships because they seem a good fit for purpose. Using diesels should mean lower operating costs and lower capital costs, lower maintenance costs. Lack of missiles means that much fewer expensive electronics to maintain, update, upgrade, calibrate, test etc. At 1800t and in steel these ships should have a long structural life, maybe 30 years.
Being new, they no doubt have modern radar, electrics, pumps etc which should be easier to maintain and additionally last longer than say equipment that has been used for 20 years. Thus I think these are a better buy that getting a cheap second hand corvette. Also 1800t is a nice size, not too big, not too small, a nice size for an OPV. End of rant.