Do it separately and put it on a 0% credit card
^^ This. If you need to spread the cost, booking a much more expensive package just to access this facility is a stupid way to do it. Many hotels don't require you to pay until you go, and there's always credit cards - if you're spending money you would have spent anyway, and arrange things so you don't pay any interest. It's a no brainer.
They also give you protection if something goes wrong - eg when Monarch went bust 2 days before we were due to travel, our credit card refunded the cost of the lost flights and the price difference as new flights were £££s in comparison. Most travel insurance doesn't cover you in these circumstances.
I've compared booking separately vs packages and sometimes packages are cheaper, sometimes booking separately is cheaper, but I've never seen such a huge difference, so I'm wondering if you're really comparing like with like, ie same room type, transfers, same time flights etc etc.
We once got a week's package in a 4* HB hotel in Tenerife for 2 of us for just £200 more than the flight alone, so the hotel, breakfast and evening meal cost less than £15 pppn.
When we went to Gozo, it was cheaper for the package than the same hotel and flights, before I'd even looked at the cost of luggage, which we needed as diving, and the ferry and 2 road transfers.