How much money is too much?

This is not uncommon. Many places just aren't set up to take credit cards. Although some have established paypal accounts. Email the rental and see what you can work out.

If you do need to take a chunk of cash then split it between you and your spouse and deep bury it in a money belt that you will not access until you arrive at the apartment.

Also ask your bank to increase your daily limit on your ATM for the duration of your trip. If your soon to be spouse has a different checking account keep it and have two sources for withdrawals. If he doesn't maybe set up one.

If you feel comfortable with the rental folks and confident in your plans then you could also send them more money up front.

I'll be in the same situation in April. I plan to get the funds in Euros from my bank here in California before my trip. I usually withdraw funds from ATMs in Europe, up to 300 Euros a day. I may count on being able to get 200 Eu in Paris, while bringing the remainder from home.

We will be carrying quite a bit of cash on us as well. We plan to split up the amounts between the two of us and bury it until we can get to the hotel safe. I will sew it into my pockets if I have to.

Nicole,

I suggest you set up an account with www.xe.com/fx. I use mine to send money to relatives in the UK and to pay for deposits at B&Bs that don't accept credit cards. Money is taken from my checking account by electronic transfer and a bank draft in the currency of my choice is mailed directly to the recipient of my choice. The exchange rate is only slightly higher than the international rate on the day the transaction is initiated and there are no other fees.

You could use XE to pay the deposit. Although I haven't done it myself, I think you could have XE mail a bank draft to you which is payable to the apartment manager and then you can hand deliver it when you get to Paris.

For security reasons it takes some time and effort to set up an account, but everything goes quickly and smoothly after that.

We chose to use groups that accepted credit card payment prior to our arrival. Much safer than carrying that much cash.
Check out iloveparisapartments.com or vacationinparis.com
Don't know what area you are looking for, but if it's the St. Germain area, send me a PM for more info.

It appears that you will be paying for the apartment the day you arrive; so you won't have to protect your money very long.

You can't depend on ATMs; so I would put it in my neck pouch with my passport and forget about it. I don't like a money belt.

For the women: I kept my cash in a baggie in my bra. Sounds silly but it was easier than the money belt. Just a quick step round the corner and i had access and no one else is gonna grab it. I kept all my pounds that way when I was in London and never worried, even when my purse did get unzippedin Piccadilly amidst a crowd. They took nothing and got.. nothing. Kept credit cards and ID in the money belt.