Mortgage rates spiked again this week and reached their highest levels in two years, ruining refinancing plans for many homeowners while anxious homebuyers try to beat the clock. The benchmark 30-year fixed-rate mortgage rose to 4.66 percent, compared with 4.48 percent last week, according to the Bankrate.com national survey of large lenders. The mortgages in this week’s survey had an average total of 0.28 discount and origination points. One year ago, that rate stood at 3.79 percent. Four weeks ago, it was 4.14 percent. The benchmark rate on the 30-year fixed has risen ...