Where to find prices?

For less commonly traded items, I tend to have problems finding prices. Specifically 3A, but if there are other items that you guys know about, I'd appreciate some advice on where to find those prices as well. I use merchz for all of the items listed there, and I price check items with a decent buy limit, I've heard 3A is good to flip, I just don't want to get in over my head by buying too high to start.

For most 2/4 items that are not commonly traded, one can profit either by
1) Buying overnight. If one buys overnight they will be able to use 2-3 limits on the item, meaning standard flipping techniques can apply (i.e., instant buying then instant selling to find prices).
2) Instant buying then lowballing. (Yes that was an awful name, but I'm not sure exactly what to call it). With certain 2/4 items one can profit by instant buying the item and deducing its high price, then reselling the instant bought item at the same high price and lowballing the item.
3) This isn't really a method of its own, but if you attempt to do method one, and the item won't instant sell for what you consider to be a very low price, then switch over to method 2. This will save you a lot of unnecessary money spent price checking.

As for third-age... it's probably the most difficult flip in the game to pull off. With lower third-age items, e.g. mage bottoms, mage hat, melee helm, I've found minor success with method 3 (albeit I haven't done it in a while). These strategies will NOT work on the higher ones though, e.g. melee top and bottom, and obviously druidic. Rough prices on these higher items can be sometimes found on the RS forum thread: Third-age status v4, but these pcs should ALWAYS be taken with a grain of salt. Perhaps two grains.

(Hope this helped, if only a little.)

I got another method phileep..

If you try to inb an item for say 15-20% over mid and it dont buy... just lowball the buy above mid.. and sell at whatever u want... thats how ive made profits on quite a few items and you know it works too hehe

Thanks for the responses guys, I've only got a little over 1b to play with, I know I can keep making money using items I currently use, is that enough for me to try 3A without too much risk? Also, is it such a slow flip that I shouldn't even bother unless I won't be playing for awhile?