Wheather the "free" gear is usable depends on a lot. Age, brand and your motivation all make a difference. Pretty much all US Divers (Aqualung) gear is easily servicable, same goes for Scubapro. Now some dealers will tell you otherwise but fact is, IF the tech wants to, most all USD/AL and SP service parts are easy to get although an "official" service kit might not be. Most other brand names that you can currently buy can also be serviced but again it depends on the motivation of the shop/tech. The older brands like Dacor, Healthways and Sportways that are no longer around can be a problem but even most of those can be serviced IF the tech is willing.
BCs are fairly easy, either they inflate and hold air or they don't. If they don't, odds are it's an easy fix. Inflators are fairly generic and easy to replace. You might not have the latest and greatest whiz bang BC but if it inflates, deflates and holds are for an hour or 2, it will work.
IMO, take option 1, several times if you can, then pick the best of the bunch and go from there. Post photos of what you have here, it's fairly easy to tell you what is worth servicing and what is best sold. Worst case, you end up selling it for parts on ebay and making a few bucks to spend on new gear.
There is also option 4 which is likely the best of the bunch. Keep an eye on the local sales adds like Craigslist. Many times fairly new gear can be had for a considerable savings.
BCs are fairly easy, either they inflate and hold air or they don't. If they don't, odds are it's an easy fix. Inflators are fairly generic and easy to replace. You might not have the latest and greatest whiz bang BC but if it inflates, deflates and holds are for an hour or 2, it will work.
IMO, take option 1, several times if you can, then pick the best of the bunch and go from there. Post photos of what you have here, it's fairly easy to tell you what is worth servicing and what is best sold. Worst case, you end up selling it for parts on ebay and making a few bucks to spend on new gear.
There is also option 4 which is likely the best of the bunch. Keep an eye on the local sales adds like Craigslist. Many times fairly new gear can be had for a considerable savings.