It all depends on whether it makes more sense to buy or rent in your area.
http://www.nytimes.com/interactive/business/buy-rent-calculator.htmlIf, for example, it would cost you $1000 to rent, but only $700 for PITI on a 15-year mortgage, it's probably much smarter to buy right away, with a mortgage. You'd have the house paid off in 15 years anyways (as opposed to saving up for 15 years and paying cash), lock it in at a (very likely) lower price now, and have more cash in your pocket (the extra $300/mo for paying 700 PITI instead of 1000 rent, though it won't always be that much because now you pay repairs instead of a landlord). If, in fact, you paid that extra 300/mo towards the mortgage, you'd pay it off in only 8 years and 8 months. That means you'd own the house free and clear in 8+ years, instead of 15 years.
A house that cost the same, mind you. Meaning you get 7 extra years to save all that money after. (Year 15 in paying cash scenario you have the paid off house and that's it. Year 15 in the mortgage scenario you have the paid off house and all the money you saved on rent/no mortgage for the last 7 years, or approximately an extra $46,000)
On the other hand, if it makes more sense to rent, it will cost you a lot more.
It all comes down to if it makes more sense to buy or rent, but if it makes more sense to buy, it almost always makes more sense to buy sooner, rather than later, if you're sure of what you want.