Eh, I was like a few hundred exp from a prayer level yesterday and didn't want to go below the 1000k mark in cash, so I thought of heading to hill or moss giants, but then it hit me, big bones offer 15 exp, and normal bones give 4.5 exp.
Thats just over 3 times as much.
But surely I could kill more than 3 chickens in the time it takes me to kill a giant?
Also factoring in the fact the F2Pers swamp hill giants like mad, and moss giants take a good 5 minutes to reach.
So yeah just a little tip for F2Pers trying to raise prayer without spending any cash; go to the larger chicken coup (the one across the bridge from Lumbridge) and just collect the bones that are left on the floor, and if worst comes to worst, just 1 hit the chickens yourself. Much faster prayer exp than battling with 100 people for 1 hill giant, that can take a few hits to kill.
Another thing I found there, is that people are starting to collect raw chickens more, due to them being 160gp each on the G.E because of summoning, but that what nobody ever collects is the bones. I decided to do a price check, and it turns out they are 185 gp each!
Just think on a packed world, you could run in, pick up 28 bones and leave in the space of 2-5 minutes! 5K for no work in minimum time.
If you were lucky, you could get a full invent banked, and return within 5 minutes, so thats 60k Gp per hour, or 1.5k prayer exp per hour if you choose to bury instead of bank. (Which is faster than most high levelled players at any form of giant.)
So yeah, this is just something to consider, and if you don't believe me, try it out yourself.
Obviously this is for F2P only though!