Supply and demand. What you wanna do is a run a poll, through either E-mail, forum, or in game (in game will get the most hits, create a message of the day that links people to forums. this incentivizes sign-ups to answer for people who would consider making purchases) and with the poll determine what it is people would be willing to pay for. List of potential goods people would buy: boosts, crate keys, t2 tomes, extra /f claim space, subscription packages that grant access to higher tiered kits (so people can just /claim and run into the warzone with some gear they would otherwise have to grind for), allowance for an LWC in this manner perhaps, not being able to use souls for LWC's would highly incentivize the purchase of them. Add all these items to the poll and ask A. should this be purchasable, answer yes or no and explain; and B. is this is a fair price for the good. That way you get answers along the lines of "I don't like the pay to win on LWC's to make bases unraidable" vs answers like "that would be a good source of server income and few enough people would purchase it to where we can still raid efficiently." As well as "if people are willing to pay for an unraidable base, they should pay $20" vs "20 seems steep, I think 10 would do."
At the end of the poll, leave a space saying: Are there any specific items you'd like to see on the market? List the good, price, and reasoning for adding it and it can be taken into consideration.
Basically, this collects the info of A. what does the consumer market demand? B. At what price will demand be high enough to not unbalance the game while being low enough to get enough purchases, and C. input for innovative ideas that can be listed as more potential sources of income.
#love_economics