Sooo I've been wondering....
is it possible for character's to purchase items from shops found all around runescape?
The Archery Shop in Varrock sells Maple Shieldbows. Would it be okay to say that one of my character's purchased a maple shieldbow from this shop?
Sure. I think there's some logic to use so obviously your character couldn't buy dragon weapons from the Monkey in the sword shop, but as far as the normal inventory is concerned there's no reason not to use that as a source. You wouldn't really even need to be that specific with such a common item.
Just out of interest, is the maple shieldbow the actual item or are you looking to use it as an example to justify something completely different?
Or, you could look around if there is a shop run by roleplayers who sells the sort of thing you want to buy.
Well, I was just wondering. Not that I want to anymore, but since everyone considers Rune Armour to be very rare, I thought of the Rune Store in the champions guild where they have several rune items in stock to purchase
I always like to assume that every city if populated by NPC citizens and guards and peasants and businesses and everything that the given city would be expected to have. That means you can expect Witchaven to be full of fishermen and fish-related services, and you can expect Varrock, market capitol of the world with the Grand Exchange in their borders, to be full of rich trade diversity for most any kind of product you want to buy.
The only difference I would address when talking about very rare products, like rune armor, is that the affordability of prices in the shops that have those rare things for sale. To us as players, paying 60k for some rune armor is like sneezing. On top of that, the prices on those items were put up based on Runescape's economy in, like, 2003 - when 100k for full rune was hard to earn and wearing a dragon med helm was a symbol of great experience and wealth.
What I'm saying is, it's completely possible that a party of adventurers from the Champion's Guild could have gone out and slain a dragon and found some rune armor in the dragon hoard and are trying to sell it so they can split the loot. However, if you agree with my ideas about the realistic value of money and items in roleplay, it would be financially devastating for even a person of great wealth to purchase full rune armor. (That is, in my system, even a person from a family of great wealth would have to live on savings and spend none of his income for 100 years before he earned the approximate suggested price of an entire suit of rune armor.) So, while walking into the champion's guild to purchase a suit of rune armor may be very feasible as an explanation for how you got it, you do still have to explain where your character got more money than a small, flourishing town's entire treasury.
That, and the current IC Champion's Guild doesn't have a Rune Store. My Co-Leaders and I got together and decided to bump that to the Legend's Guild, partially due to how easy it is to get into the Champion's Guild, and partially because the sale of Rune there is a Game Mechanic reward for the Dragon Slayer Quest.
What do you think?