There is no financial advantage in buying acrylics over enamels. In fact when you add certain products such as airbrush cleaner, flow enhancer it begins to be considerably more expensive to use acrylics over enamels.
I use enamels, thinned with white spirit which is cheap as chips.
However, if smell isn't a problem I would recommend you try either Tamiya acrylics or Mr Hobby Aqueous & thin either or both with cellulose thinner.
You'll avoid all the typical problems associated with using acrylics (clogging, tip dry etc) and get a beautifully smooth finish. You'll also not need to use primer because the use of the cellulose will mean the paint grips perfectly.
I should add that the use of primer is not just to make sure acrylics grip. It is also to show up flaws in the build to enable corrective action while also providing a consistent basis on which to apply your top coat. The latter is particularly important when using different materials plastic alongside p.e. and/or resin. In any case you should always use a primer when applying metallics of whatever type as these really emphasise build flaws.