>>1591481>say less than $300That isn't even entry-level price for a new camera. You might get a second-hand camera for that price, but it will be seriously used. Shutter count is the biggest concern. If a camera has a high shutter count then it won't have much life left in it before the shutter mechanism breaks and needs an expensive repair. If you get a used camera, try to get one with the lowest shutter count possible. You might be able to get a good lens for that price.
>compact/lightweightMirrorless
>ruggedPentax DSLR
Lenses for either will be where the weight and size factors come into play. Telephoto lenses will be bulky and heavy. Pancake lenses are small and light. The trade off to a point-and-shoot camera is the Image Quality. They will be compact, lightweight, might be rugged, but their IQ will be shit when compared to an entry level DSLR with a good lens. Only a few DSLRs will be weatherproof and you need to match lenses to them that are also weatherproof, if you need that weatherproofing that is. The same goes for mirrorless.
Ebay is effing amazing for getting good deals on used lenses. Just watch out for "haze" and "fungus" in the descriptions. Also check,
amazon.comkeh.comadorama.cometsy.comYou can use lenses from other camera too, but only if there's an adapter for them. Mirrorless cameras have the shortest Flange Focal Distance and as such can use more types of lenses from other manufacturers using an adapter.
>>1591684Most people buy expired film online and develop their own exposures and dark room work. You don't need separate lenses per se. If DIY things, I recommend you try it. You can buy the gear or build your own cheap pinhole camera that uses either film or photopaper then develop it yourself. Photopaper ASA/ISO developing is a bit different from film so make sure to read up on it online using a few different tutorials. Pinhole + photopaper developing is the cheapest method, but exposure times take forever (minutes to hours.)