First of all, I would think you would want to use a paint that will last the longest on the mast since you are going to go through all of this work in the first place. Budget, of course plays a role, but if your budget is 17 bucks, I guess you get a 17 buck paint job. Any urethane paint should be better for gloss retention, abrasion resistance and longevity than an other paint like epoxy (top coat type) which doesn't hold up to sunlight very long, or Alkyds, etc. Two part urethanes are the best, such as the linear polyurethane that Awlgrip provides in either Awlgrip or Awlcraft (the latter being not as hard and therefore more repairable and also more VOC compliant).
But, Awlgrips are much more expensive than the Brightside paints (which are good basic do it yourselfer paints at a more reasonable price). Interlux also has two part urethane paints for brushing which are very good, but your color selection is limited in comparison to Awlgrip. But then, most masts are painted white or black, I guess.
With any paint, you want to follow the recommended system offered by the manufacturer. This should be pretty straight forward and if followed, you won't go too wrong. Aluminum requires more proper prep for longevity than say, fiberglass painting. Off the top of my head (I don't have product info in front of me), on an aluminum mast, you want to sand it all to bare, scuffing it up to remove all earlier applied paint, if previously painted or remove any oxidation and to provide a tooth for your paint.
Then you want to clean the mast. Awlgrip says to wash the mast with Alumiprep 33 (I believe that is the name) and then etch it with an Alodine solution (1201 or something like that). Then you paint on a yellow zinc chromate primer (can't recall the nomenclature right now - it has a Y in the name, I believe) and then apply the two part epoxy primer 545 on that. Then you are ready for the color of choice. If you need to do some fairing then fair AFTER you apply the primer. Don't put fairing compound on the bare aluminum or that is where you will have paint failure down the road. Apply the primer, use the fairing compound and prime over it again.
You can spray Awlgrip (us Awlcat #2 catalyst) or brush/roll it (using Awlcat #3). There are different reducers to thin the paint for spraying for various temperature conditions. And, if you want, you can add excellerators to cure the paint quicker.
This is enough info to get you started. Awgrip has a very detailed pamphlet/book to obtain the necessary info on prep, painting application, etc.
BTW Interlux has a bilge coat paint designed for bilges for those who brought up that issue.
), I'd opt for a two part paint like Interlux Perfection as opposed to Brightsides. Tim R. Just did his spar two years ago and it came out looking pro quality but he took his time and probably has more than 80 hours into it with removal of all hardware, prep, prime and re-finish.. 
