Welcome to HCM.
You should go for MTP
as there is no solution in saying that you can't afford inj i.e. too costly.
In absence of injection you can't prolong the pregnancy
as it will heart more. and after a time your wife will abort itself.
There is no incompatibility in A+ and O+ parental groups so no question of costly inj arises.
So you don't need the costly inj of RH+ Father and Rh-v Mother for future prevention of miscarriage
If you do not need any further pregnancy than this inj is not needed its of no utility in this case as there will arise no condition of miscarriage with no pregnancy.
Get well soon.