Magic weapons that you can purchase Virtus wand and book however they're much more expensive than Drygores. Seismic wand and RS gold singurarity are insanely expensive The price in the ge says the wand's value is 500 million dollars, but it's actually worth 2Bish. If you're looking to shell out a fortune, buy an Arma battlestaff, it's less effective than a Chaotic staff but it's superior to SoL at a minimum.
With the advent of the grand exchange, objects can be exchanged for cash easily, and could effectively be considered the exact same thing. Let's say (hypothetically) you need 100k cannonballs in order to slay, and can afford 200k for 250gp each. If you invest 25000k 100k cannonballs to 300gp each, you'll be left with 30000k which you can convert to cash or use. Additionally, if cannonballs are reduced to 200gp each and you have 20000k, which you can make cash payments or use.
Doubling the investment is simply doubling the return, whether it's the case of positive returns or negative. If you think that buy OSRS gold the price of cannonballs will increase, you should invest the amount you'd like into them. The higher your investment will be, the more likely you are to earn profit on whatever you don't get to use. If you decide to purchase less cannonballs than what you'll need in the event that they increase, you'll have to buy the remainder at a more expensive cost.