Low interest rate purchase
Consider a 891 sq. ft, 2 bed / 2 bath condo in South Edmonton suburb of Ellerslie. The asking price is $199,000.

With $19,900 down the initial mortgage balance is $179,100. The mortgage is as follows assuming a 5-year fixed rate of 4.10% and 25 year amortization.
2009 Purchase price: $199,000
Down payment: $19,900
Initial balance: $179,100
Rate: 4.1%
Monthly payments: $951.84
2014 Balance: $156,184
Rent for two years and purchase with higher rates
Compare this to waiting for two years and taking out a 5-year fixed at 7.10% at three different prices. One will be a market crash of 30%, one only 10% and another with zero appreciation. In each of these cases there will be some gain on the down payment and some difference between the cost of renting and owning.
If we expect to use this down payment in 2 years its not going to be put at huge risk. Lets go with 3%. After two years the down payment grows to $21,112
Even with these low interest rates there is a small premium to own. First assume this apartment rents for $1200 including utilities. An owner will need to add $270 for condo fees, $50 for power and $120 taxes. So the monthly savings renting is ($952+$270+$50+$120)-$1200 = $192. After two years that adds up to $4,608. So total down payment is $25,720 after two years in each of the wait cases.
Wait case #1: 30% decrease
After a brutal decline the purchase price of an equivalent condo decreases to $139,930. I am comparing the balance after 3 years to have this case line up in time with the one that bought immediately. The mortgage terms are as follows:
2011 Purchase price: $139,930
Down Payment: $25,720
Initial balance: $114,210
Rate: 7.1%
Monthly payments: $807.01
2014 Balance: $108,578
This case shows that low interest rates are not enough to offset a market crash (duh!). Not even close as both monthly payments for the initial term and final mortgage balance after 5 years have elapsed are lower. Amount lost on difference in monthly payments over three years is $5,213 and the difference in mortgage balance is an additional $47,606. Total lost buying with low interest rates before a 30% crash: $52,819.
Wait case #2: 10% decline
The purchase price of an equivalent condo is $179,100 with the following mortgage terms:
2011 Purchase Price: $179,100
Down Payment: $25,720
Initial balance: $153,380
Rate: 7.1%
Monthly payments: $1083.79
2014 Balance: $145,816
In this case the reduction in payments with low interest rates($4,750) is not enough to offset the higher mortgage balance at the end of the term (-$10,368). Total lost buying with low interest rates before a 10% correction:$5,618.
Wait case #3: No appreciation
The purchase price of an equivalent house remains at $199,000 with the following mortgage terms:
2011 Purchase Price: $199,000
Down Payment: $25,720
Initial Balance: $173,280
Rate: 7.1%
Monthly payment: $1224.40
2014 Balance: $164,735
This case shows in absence of any price decline, the amount low interest rates benefit the original purchaser. The amount save on payments due to low interest rates for the three years the mortgage terms overlap is $9,812 and the balance is $8,551 less. Total gained by buying with low interest rates $18,363.
Low interest rates save the buyers money if we assume no, or only a minor market correction once rates increase.