We'd love to hear more of your questions about money and the economy. You can send through written questions, like these ones, but even better, you can drop us a voice memo to our email questions@rnz.co.nz.

I was wondering about the currency conversion charges that banks and credit card companies add when you make a non-NZ dollar transaction. Is there a real cost to banks, or is it just another way of clipping the ticket? My feeling is it's the latter and, as it already seems to me that banks offer a lower exchange rate than, for example, the rates we hear broadcast on RNZ each day, maybe they're clipping the ticket twice. I can't imagine currency conversion involves a bank teller banging away at an adding machine, but perhaps my cynicism is misplaced. Disabuse me, if you can. But if there is no real cost here, I do wonder what these practices add to bank profits each year.

I wasn't sure myself, so I went to ask the banks. Westpac told me that the currency conversion fee on its consumer credit cards was designed to cover the costs it was charged to make the transactions, and was cost-neutral.

Claire Matthews, a banking expert at Massey University, said there was a real cost to the transactions but it was about profits as well.

"The banks need to maintain foreign exchange holdings to back these transactions, plus there are the costs of the transactions - as with all transactions. There is also an exchange rate risk associated with transactions in another currency, because the exchange rate may change between the time the transaction occurs and it is finally settled.

"The difference noted between the rates reported by RNZ and charged for transactions, is simply because the former is the wholesale rate that applies for large - millions of dollars - transactions which has lower transaction costs and the latter is the retail rate."

She said there were an increasing number of alternatives for international transactions that could offer better exchange rates or lower fees, so if you were worried about incurring them regularly, you could look at other options.

How much money can be put into your KiwiSaver? Is there a limit?

No, there's no limit.

When you're making contributions from your pay, you can set the amount at anything up to 10 percent. But you can make any additional voluntary payments you want to on top of that.

You might hear other countries talking about limits on what can go into super savings, but that is generally because there is a tax incentive associated with that. In New Zealand, we don't have those perks so there is no limit.

Whether it's appropriate to put your extra investment in there will depend on your wider circumstances, though.

My wife and I are recently retired with a mortgage-free property with a value of approximately $2.6m. We have $900,000 cash and are interested in your thoughts on how best to utilise these funds. The funds are currently sitting in a bank term deposit due to become available.

We are well travelled and will not go far moving forward, maybe one more European trip and annual Gold Coast holidays. We have a reasonable appetite for risk. We have never been involved in the share market but retain an open mind around various opportunities.

Ana-Marie Lockyer, chief executive at Pie Funds, said it's probably worth taking some more risk with at least some of your money.

"Holding $900,000 entirely in cash protects you from share market volatility but exposes you to inflation and the risk that your money doesn't grow sufficiently over a long retirement."

She said she might suggest you put some of your money into a diversified portfolio including some shares.

"Given the amount involved and the fact they are entering a new stage of life and new to investing, now would be a good time to sit down with a financial adviser. An adviser can help them think through what they want their retirement to look like, how much income and access to capital they are likely to need, and what their longer-term goals are.

"From there, they can work out an appropriate mix of cash, income and growth assets that reflects both those needs and their appetite for risk. The aim shouldn't simply be to take more risk for the sake of higher returns, but to make sure their $900,000 is invested in a way that gives them the right balance of security, flexibility and long-term growth."