ABF's go in pritty quickly and they arn't that expensive
no way is a 2.0 8v in std trim going to make 150 bhp on carb without fetteling to the cyl head.
priceing work on old cars is generaly not done as you don't know what you'll find so if doing the job properly it's not possible if your just going to ignore potential dragons it is but thats wrong.
ABF on abf managment will be cheepest and offer most poke for your pounds, that will present 150+ bhp as it is out the box no fuss no bother all day long and give you 40+ mpg