Any chance you could do both? I had a Moby wrap (only $30ish) and a Baby Bjorn. The Moby was great when he was still a little bitty... he could sleep in it while I did stuff around the house, etc. But the Baby Bjorn has proven to be essential... we STILL use it & my son just turned 1! Grocery, DisneyWorld, church, walks... I use that sucker all the time and will be in a period of mourning when he reaches the weight limit!!!
So if you could only choose one or the other, I'd do a carrier. Easier to put on, husbands can figure it out, goes to a higher weight limit, gives you that "secure" feeling because of the buckles & straps.
But best case scenario, just go for both! Especially since most slings or wraps aren't too overly pricey.
Good luck, and happy baby-wearing!