I truly need something like a free for OSRS gold all arena as a safe minigame. It could be really fun and great XP. The region would be on the size of the fist of guthix stadium with a great deal of challenges, ranging towers. . .etc. It won't provide runes, but it is going to yield about 60 percent of the runes you've used.
Just like the arrows burst. Now there shouldn't be any such a thing as complimentary XP. For in this area, you will have to purchase the time that you are planning to play.
Just to make it fair for the men and women that have a hard time earning money. Bandages could be provided along with a milder version of the strength potion. The area can be divided into to segments: Place with levels (such as the wild) where you can just attack opponents near your level. A free for all area.
I think that there should be no need for buy RS gold benefits as it would be pretty fun how it is. For people to not acquire super speedy XP by 1 hitting noobs all day you could get a smaller amount of XP gained (much like battling arbitrary events).