My local pet store is a petco... and they charge about 3 bucks a mouse.

Petsmart charges 5 bucks a mouse and won't sell to you if they know you have a snake.

If you only have the one snake I'd go with the mousicles. Buying f/t is very economical because you can buy a lot and they will last you a long time. Invest in a vacuum sealing system, one of the cheap ones like the ziplock pump (4.50 for the starter kit, and you can reuse the bags if you're careful) or the reynolds kit ($14 but it's battery operated so I like it, it's what I have). That way you can re-seal the mice every time and they will be 'fresh' longer. Basically you've got to factor how many your snake will eat in a month so you know about how many you should buy, usually no more than 6-7months worth. Then find out how much it will cost to ship that many mice and figure cost per mouse, it's usually way cheaper.... especially if you've been paying 3bucks a pop.

My fave online dealer was themousefactory.com

I used to by online but I'm breeding because I was buying a lot and they we'ren't lasting a long time. I went from one snake to four and the shipping cost was doubling the price of the mice. Plus I like raising the little suckers. If done right mice don't smell too bad. But it can be a lot of work so...